Correct location of the circulation pump in the heating system. The procedure for installing the pump in the heating system. Calculation of circulation pump flow for heating

In heating systems with natural and forced circulation, a circulation pump is used. This is a device that changes the speed of a fluid without changing the nominal pressure. In a heating system it is needed for efficient heating. Installing a circulation pump is not a difficult task; with minimal skills in this work, you can do the installation yourself.

Features of circulation pumps

In systems with a forced circulation system, a pump is installed to increase heat capacity. Correct installation of the circulation pump in the heating system allows you to change the heat that is transferred depending on the outside temperature while maintaining stability of the heating in the room.

There are two types of such equipment: with dry and wet rotor. Devices with a dry rotor have increased efficiency (about 80%), do not create much noise and require constant maintenance. The operation of a device with a wet rotor is different; it has a low efficiency (about 50%), is noisier, and its performance is sufficient to heat any private home.

30 years ago, houses used so-called vertical central heating, which was powered by liquid circulating through pipes, and the heat source was a gas boiler or wood-burning stove. Now there has been a transition to the construction of private housing using heaters with a pump, which has the following advantages:

The coolant speed increases.
The heat produced by the boiler is quickly delivered to the radiators and returned to its place.
The heating process is significantly accelerated.
The speed is higher, so the same amount of heat can be supplied to pipes with a smaller diameter. In other words, a pipe with forced circulation of water in a pump is cheaper. The barrel can now be wrapped with minimal deflection and added complexity. The main thing is to make the correct selection of the pump unit and set the pressure.
An internal pump for circulating water in the heating system made it possible to have heated floors and efficient closed systems operating under high pressure.
We managed to remove the pipes that run along the walls and do not always harmonize with the kitchen interior. Nowadays, heating lines are built into the walls, under the floor and behind the suspended ceiling.

As the main disadvantage of the pumps, it can be noted that if there is a need to frequently turn off the circulation pump, a generator must be installed or connected.

Device operation

Despite the large amount of information, many find it difficult to understand where and how to properly install a circulation pump to ensure forced circulation of water in the home heating system. You need to follow the instructions. Often this the block is located on the return pipeline, which leads to the following situations:

The temperature of the liquid in the supply is much higher, so the pump does not work.
Hot water is less dense.
The static pressure in the pipeline is higher, which facilitates the operation of the device.

Sometimes, when you get into a room where a boiler is installed that provides heating in the apartment, you can see that the system is based on return. We can say that this is the only correct solution, even if you don’t know about the centrifugal device that can be installed in the outlet pipe.

In an emergency and as a result of an increase in pressure, a safety valve is activated, which releases steam from the boiler. If the action is not completed, the valve allows pressure to be released, resulting in an explosion of the boiler shell.

Experience shows that no more than 5 minutes after the start of the heating process, the safety valve is activated. If you install the device on the return pipeline, steam will not appear in it, and the time before an accident will increase to 20 minutes. That is, if you install a check valve, you cannot prevent an explosion, but you can delay it in order to gain time to make a decision.

Pump operating principle

Circulators operate on electricity. There are two approaches to the system, which leads to their division into “dry” and “wet” type devices. The principle of operation of a dry chain is that the drive is completely isolated from each pump and turbine, and rotation is transmitted through the shaft. As a rule, such devices are quite massive.

Dry pumps for circulating water in a heating system are powerful and efficient devices that provide very high flow rates and high pressure in the system. Without them it is difficult to control the heating. They must be installed in an apartment or private house. However, there are some disadvantages:

The shaft that transmits rotation is a complex sealing system that prevents leakage of liquid under pressure. These seals gradually wear out, requiring regular preventive maintenance, including replacement with new ones.
The operation of the pump is always accompanied by an air-cooled sound effect.

Finally, the system is a very expensive choice; the best option would be to purchase a wet rotor pump. The vertical wet rotor pump also comes in different types.

One-pipe and two-pipe systems

Experts distinguish between two heating schemes with forced circulation of the thermal agent - one-pipe and two-pipe. The choice of one or another option determines not only the location of the circuits, but also the length of the pipelines, as well as the type and quantity of equipment for shutdown, regulation and control.

A single-pipe heating system is characterized by the sequential inclusion of heating radiators in the circuit. The coolant returns through a separate pipeline to the boiler only after it turns one by one through all the devices of the system. The disadvantage of this method is that radiators that are closer to the thermal block become warmer than those further away, and this reduces thermal efficiency and equipment life. Introducing a circulation pump into the circuit and equalizing the temperature is achieved at all points of the system.

A two-pipe arrangement has advantages over a single-pipe arrangement, since all heating devices are connected in parallel to the supply and return lines, which promotes uniform temperature distribution throughout all rooms. Forced circulation of the refrigerant leads to increased efficiency of the system and the ability to regulate its thermal power.

DIY installation

It is important to know how to properly install a heating pump. You also need to know which pump to install in the heating system. Each unit comes with instructions that you will study carefully to ensure you can complete the installation yourself correctly. All liquid is drained from the system, part of the pipe is cut off in the place where the pump is to be installed.

In many cases, an old system that has accumulated dirt and rust will need to be cleaned. It is inconvenient to do this through the drain valve due to the small cross-section of the hole, so use the cut point. A hose is connected to one side through which water is fed under pressure, and on the other side the water flows out.

A bypass is installed at the pump site. This is necessary in case of device failure or power outage. The coolant will then flow through the main line, which is manually opened. It is better to install an automatic one instead of a conventional ball valve, which reacts to changes in pressure in the system.

On the bypass, two ball valves are placed on each side of the pump to turn off the water for maintenance or, if necessary, remove it. At the top of the bypass line, install the air release valve vertically. It is recommended to install the pump use the following sequence of actions:

Drain the water and clean the heating system.
For a system that has been in use for a long time, it is recommended to flush it a couple of times, filling it with water and then draining it.
Install the purchased pump into the designated location according to the plan, following the principle of energy management.
After installation, fill the device with liquid (water).
Check the operation of the heating system. In case of any errors, their strict correction is necessary.
Remove accumulated air from the system using the central screw. Outgoing water is a sign that the operation was carried out correctly.
Turn on the built-in pump after filling it with water. When connecting equipment to the network, it is recommended to use an automatic fuse with a special flag.

The fuse has an additional function as a switch. To install an additional pump in the system, please note that it turns on only after a relay signal. To synchronize the operation of both pumps, you need to connect the second device to the relay or use an alternative parallel connection.

Filter installation

In order for the pump to work more reliably and longer, the coolant passing through it must be absolutely clean. Otherwise, the bearings and impeller may simply be destroyed by foreign objects getting into them. The dirt filter, which is installed in front of it during the cooling process, captures all contaminants, sand and other small abrasive particles that appear in the system. Filters can always be changed.

As a dirt filter, you can use a regular coarse filter used in a water supply system. This is a small piece of pipe with an external dirt trap.

The straight cut has a metal structure that cuts out debris that could damage equipment. All debris should settle in the pipe, which can be periodically cleaned by unscrewing the plug at its end. Clogging must not be allowed.

Circulation pumps are installed in heating systems with forced or natural circulation. It is needed to increase heat transfer and to be able to regulate the temperature in the room. Installing a circulation pump is not the most difficult task; if you have a minimum of skills, you can do it yourself, with your own hands.

What is a circulation pump and why is it needed?

A circulation pump is a device that changes the speed of movement of a liquid medium without changing pressure. In heating systems it is installed for more efficient heating. In systems with forced circulation it is a mandatory element, in gravity systems it can be installed if it is necessary to increase the thermal power. Installing a circulation pump with several speeds makes it possible to change the amount of heat transferred depending on the outside temperature, thus maintaining a stable temperature in the room.

Cross-section of a circulation pump with a wet rotor

There are two types of such units - with a dry and wet rotor. Devices with a dry rotor have a high efficiency (about 80%), but are very noisy and require regular maintenance. Units with a wet rotor operate almost silently; with normal coolant quality, they can pump water without failure for more than 10 years. They have a lower efficiency (about 50%), but their characteristics are more than sufficient for heating any private home.

Read about choosing a circulation pump for heating systems here.

Where to put

It is recommended to install a circulation pump after the boiler, before the first branch, but on the supply or return pipeline - it doesn’t matter. Modern units are made from materials that can withstand temperatures up to 100-115°C. There are few heating systems that work with a hotter coolant, so considerations of a more “comfortable” temperature are untenable, but if you feel safer, put it in the return line.

Can be installed in the return or direct pipeline after/before the boiler up to the first branch

There is no difference in hydraulics - the boiler, or the rest of the system; it makes absolutely no difference whether there is a pump in the supply or return branch. What matters is the correct installation, in the sense of strapping, and the correct orientation of the rotor in space. Nothing else matters.

There is one important point regarding the installation location. If the heating system has two separate branches - on the right and left wings of the house or on the first and second floor - it makes sense to install a separate unit on each, and not one common one - directly after the boiler. Moreover, the same rule remains on these branches: immediately after the boiler, before the first branch in this heating circuit. This will make it possible to set the required thermal conditions in each part of the house independently of the other, and also in two-story houses to save on heating. How? Due to the fact that the second floor is usually much warmer than the first floor and much less heat is required there. If there are two pumps in the branch that goes up, the speed of movement of the coolant is set much lower, and this allows you to burn less fuel, without compromising the comfort of living.

Harness

There are two types of heating systems - forced and natural circulation. Systems with forced circulation cannot work without a pump; systems with natural circulation work, but in this mode they have lower heat transfer. However, less heat is still much better than no heat at all, so in areas where electricity is often cut off, the system is designed as hydraulic (with natural circulation), and then a pump is installed into it. This gives high heating efficiency and reliability. It is clear that the installation of a circulation pump in these systems is different.

All heating systems with heated floors are forced - without a pump, the coolant will not pass through such large circuits

Forced circulation

Since a forced circulation heating system without a pump is inoperative, it is installed directly into the gap in the supply or return pipe (of your choice).

Most problems with the circulation pump arise due to the presence of mechanical impurities (sand, other abrasive particles) in the coolant. They can jam the impeller and stop the motor. Therefore, a mesh dirt filter must be placed in front of the unit.

Installing a circulation pump in a forced circulation system

It is also advisable to install ball valves on both sides. They will make it possible to replace or repair the device without draining the coolant from the system. Turn off the taps and remove the unit. Only that part of the water that was directly in this piece of the system is drained.

Natural circulation

The piping of the circulation pump in gravity systems has one significant difference - a bypass is required. This is a jumper that makes the system operational when the pump is not working. One ball shut-off valve is installed on the bypass, which is closed the entire time the pumping is running. In this mode, the system operates as forced.

Installation diagram of a circulation pump in a system with natural circulation

When the electricity goes out or the unit fails, the valve on the jumper is opened, the valve leading to the pump is closed, and the system operates as a gravity system.

Installation features

There is one important point, without which the installation of the circulation pump will require rework: it is necessary to rotate the rotor so that it is directed horizontally. The second point is the direction of flow. There is an arrow on the body indicating which direction the coolant should flow. This is how you turn the unit so that the direction of movement of the coolant is “in the direction of the arrow”.

The pump itself can be installed both horizontally and vertically, just when selecting a model, make sure that it can work in both positions. And one more point: with a vertical arrangement, the power (pressure created) drops by about 30%. This must be taken into account when choosing a model.

Power connection

The circulation pumps operate from a 220 V network. The connection is standard; a separate power supply line with a circuit breaker is desirable. The connection requires three wires - phase, neutral and ground.

Circulation pump electrical connection diagram

The connection to the network itself can be organized using a three-pin socket and plug. This connection method is used if the pump comes with a connected power wire. It can also be connected via a terminal block or directly with a cable to the terminals.

The terminals are located under a plastic cover. We remove it by unscrewing several bolts and find three connectors. They are usually signed (the pictograms are N - neutral wire, L - phase, and “ground” has an international designation), it is difficult to make a mistake.

Where to connect the power cable

Since the entire system depends on the performance of the circulation pump, it makes sense to make a backup power supply - install a stabilizer with connected batteries. With such a power supply system, everything will work for several days, since the pump itself and the boiler automation “pulls” electricity to a maximum of 250-300 W. But when organizing, you need to calculate everything and select the battery capacity. The disadvantage of such a system is the need to ensure that the batteries do not discharge.

How to connect a circulator to electricity through a stabilizer

stroychik.ru

Installing a heating pump: how to install a pump in a heating system

To distribute heat evenly in a house equipped with an autonomous heating system, various models of circulation pumps are used. This equipment provides forced circulation of coolant through pipes and radiators. In this case, the radiators are heated simultaneously in all rooms, regardless of their distance from the heating boiler. The heating pump is installed in accordance with the manufacturer’s instructions, which describe in detail the installation process of this equipment. In practice, several methods of arranging pumping units in the heating system of a private house have been tested. In each case, the owner of the facility selects the most suitable option, taking into account the type of boiler and expansion tank used, the type of heating system, and the presence of additional elements.

Selecting the right unit

When choosing a pump, pay attention to two main parameters: the strength of the coolant flow and the hydraulic resistance that it overcomes when creating pressure. In this case, the characteristics of the purchased circulation pump should be 10-15% lower than the calculated values. If you install a powerful pump in the heating system, you may encounter the problem of increasing power consumption, excessive noise, and rapid wear of equipment parts. A low-power pump will not be able to pump coolant in the required volume. Many models of modern circulation pumps are equipped with electronic or manual controllers for the speed of rotation of the electric motor shaft. The highest efficiency value is achieved at maximum shaft speed.

Thermal valves installed in many heating systems regulate the room temperature in accordance with the specified parameters. The valve closes when the temperature rises. This increases hydraulic resistance and, accordingly, increases pressure. These processes are accompanied by the appearance of noise, which can be eliminated by switching the pump to low speed. Pumps with built-in electronics that can smoothly regulate pressure drops depending on changes in the amount of water cope with this task more effectively.

Read more about how to choose such a pump in the articles: Selection of a circulation pump for heating and Calculation of a circulation pump for heating in examples and formulas.

Determining where the pump is inserted into the system

Correct operation of pumping equipment is possible provided that the location of its insertion into the pipeline is correctly determined. The pump must force the coolant to circulate through the heating system, thereby ensuring rapid movement of hot water from the boiler to all radiators installed in the house. This is what a typical heating circulation pump connection diagram looks like, most often used by specialists in practice.

Typical diagram for connecting a pump providing forced circulation of coolant to an autonomous heating system of a private house or country cottage

Its main elements are the boiler (1), membrane tank (7), pump (5), heating radiators (8), as well as:

coupling connection (2);
valves (3);
alarm system (4);
strainer (6);
heating system water supply line (9);
management (10);
temperature sensor (11);
emergency sensor (12);
grounding (13).

In autonomous heating systems, sealed pumps with a throttleless “wet” rotor are usually installed. These models do not require additional lubrication of parts or replacement of gaskets. These functions are performed by the coolant. The water pumped by the pump also cools its elements and also ensures silent operation of the equipment. The throttleless pump body is made by manufacturers from cast iron, and the rotor is made from steel or wear-resistant plastic. The device, which does not require intensive maintenance, can operate for 20 years or more.

Basic installation rules

Any equipment is supplied accompanied by the manufacturer’s instructions, which reflect all the important information about its design, operating principle and installation rules. After reading this technical document carefully, you can understand the basic rules for handling it.

When installing it yourself, it is very important to choose the desired position of the product relative to the horizon. The location of the electric motor shaft must be strictly horizontal. Otherwise, air pockets may form, which will leave the bearings without lubrication and sufficient cooling. This will lead to rapid wear of parts and rapid equipment breakdown. There is an arrow on the pump body in the direction in which the coolant in the system should move.

Options for correct and incorrect placement of a circulation pump with a “wet” rotor. It is strictly prohibited to place equipment as shown in the bottom row.

The need for water filtration

A sump tank is installed in front of the pump, the function of which is to filter the coolant. The mud filter traps abrasive particles, sand, scale and other contaminants that get into the water. If such elements get inside the pump, the impeller and bearings may be destroyed. Since the diameter of the insert for mounting the pump is small, you can use an ordinary coarse filter. Please note that the barrel, which serves to collect various suspensions, is directed downward. Being in this position, the filter will not serve as an obstacle to water circulation. When partially filled, the barrel will not lose its ability to pass coolant.

Important! Most filters are equipped with an arrow indicating the correct direction of water flow in the circuit. If you ignore the direction of the arrow, you will have to clean the mud pan much more often.

Pump location in the heating circuit

In principle, most models of modern pumps can work equally well on both supply and return. The equipment can be installed in any part of the heating circuit. It should be taken into account that the duration of operation of the bearings and plastic parts of the device will depend on the temperature of the coolant. Therefore, it is better to install the equipment on the return pipeline after the expansion membrane tank and before the heating boiler.

One of the options for correctly inserting a circulation pump into the pipeline of the heating system of a private house with a circuit length of no more than 80 meters

Why is bypass needed?

The circulation pump is a volatile device. When there is a power outage, the heating system must operate under natural circulation conditions. To do this, it is necessary to minimize resistance in the circuit by reducing the number of bends and turns, as well as using modern ball valves as shut-off valves. When open, the clearance in the ball valve coincides with the diameter of the pipe.

The circulation pump is installed on a bypass, which is cut off from the main system using two ball valves. This placement of the equipment allows it to be repaired or replaced without damaging the heating system of the house. In the off-season, the heating system can operate without a pump, which is shut off using the same ball valves. When frost intensifies, the pump is put into operation by opening the shut-off valves along its edges and closing the ball valve on the main circuit. This is how the direction of coolant flow is adjusted.

Installation of the circulation pump on the bypass (bypass pipe) using three ball valves ensures the coolant flow in the desired direction

Electrical connection

If the heating system is designed on the principle of forced circulation, then in the event of a power outage the pump must continue to operate from a backup power source. Therefore, it is recommended to install an uninterruptible power supply that will allow the heating system to function for a couple of hours. This time is usually enough for specialists to eliminate the cause of an emergency power outage. External batteries connected to a backup power source can extend the battery life of the equipment.

Connecting the pump to an uninterruptible power supply (UPS), which is additionally reinforced by three battery units connected in series into a single circuit

When making electrical connections to the equipment, it is necessary to eliminate the possibility of moisture and condensation getting into the terminal box. A heat-resistant cable is used if the coolant heats up in the heating system by more than 90° C. Contact of the power cable with the walls of pipes, the engine, or the pump housing is not allowed. The power cable is connected to the terminal box from the left or right side, and the plug is rearranged. When the terminal box is located on the side, the cable is inserted only from the bottom. And yes, grounding is required!

Checking operation and putting it into operation

After completion of installation work, the heating system is filled with water. The air is then removed by opening the central screw located on the pump housing cover. The appearance of water will indicate the complete removal of air bubbles from the device. After this, the pump can be put into operation.

After reading the instructions and reading this article, you can carry out the installation work yourself. If you don’t understand, then invite a professional master.

aqua-rmnt.com

How to properly install a circulation pump for heating in a private home

To make heated water flow more cheerfully through the pipes, a circulation pump is installed in the heating systems of private houses. This solution provides tangible advantages, which we will briefly introduce to you. But the main question that concerns homeowners and is covered in this material is where it is better to install the pump and how to install it correctly. After all, the main part of the controversy and doubt is caused by the place where the unit is inserted. And at the same time, we’ll figure out how to connect it to the house electrical network with our own hands.

What are the benefits of pump heating systems?

30 years ago, so-called steam heating was common in private homes, where a coolant was used that circulated through pipelines and radiators by gravity, and the heat source was a gas boiler or wood stove. Pumps for pumping water were used only in district heating networks. When more compact units appeared, they migrated to private housing construction, as they provided the following advantages:

The speed of coolant movement has increased. The heat generated by the boiler has become faster delivered to the radiators and transferred to the premises.
Accordingly, the process of heating the house has accelerated significantly.
The higher the flow rate, the greater the throughput of the pipe. This means that the same amount of heat can be delivered to rooms through lines of smaller diameter. Simply put, the pipelines have become half the size thanks to the forced circulation of water from the pump, which is cheaper and more practical.
Highways can now be laid with a minimum slope and water heating circuits can be made as complex and extended as desired. The main thing is the correct selection of the pumping unit in terms of power and pressure created.
The household circulation pump for heating has made it possible to organize underfloor heating and more efficient closed systems operating under pressure.
It was possible to remove from view the ubiquitous pipes that run through the rooms and do not always harmonize with the interior. Increasingly, heating communications are laid in walls, under floor coverings and behind suspended (suspended) ceilings.

Note. A minimum slope of 2-3 mm per 1 m of pipeline is needed to empty the network in case of repair or maintenance. Previously, it was made at least 5 mm / 1 m.p.

Pumping systems also have disadvantages. This is a dependence on electricity and its consumption by the pumping unit during the heating season. Therefore, if there are frequent power outages, the circulation pump must be installed together with an uninterruptible power supply unit or connected to an electric generator. The second drawback is not critical; if you select the power of the device correctly, then the electricity consumption will be acceptable.

For reference. Leading manufacturers of heating equipment, such as Grundfos or Wilo, have developed new models of units that can save energy. For example, if you buy and install an Alpfa2 circulation pump from the Grundfos brand, it will automatically change its performance depending on the needs of the heating system. True, its price starts from 120 USD. e.

New generation products from Grundfos - models Alpfa2 and Alpfa2L

Where to install the pump - supply or return

Despite the abundance of information on the Internet, it is quite difficult for the user to understand how to properly install a heating pump in order to ensure forced circulation of water in the system of their own home. The reason is the inconsistency of this information, which causes constant debate on thematic forums. Most of the so-called specialists claim that the unit is installed only on the return pipeline, citing the following conclusions:

the coolant temperature in the supply is much higher than in the return, so the pump will not last long;
The density of hot water in the supply line is less, so it is more difficult to pump;
The static pressure in the return line is higher, which makes the pump easier to operate.

Interesting fact. Sometimes a person accidentally ends up in a boiler room that provides central heating for apartments, and sees the units there embedded in the return line. After this, he considers this solution to be the only correct one, although he does not know that in other boiler houses centrifugal pumps can also be installed on the supply pipe.

We respond to the above statements point by point:

Household circulation pumps are designed for a maximum coolant temperature of 110 °C. In a home heating network it rarely rises above 70 degrees, and the boiler will not heat the water more than 90 °C.
The density of water at 50 degrees is 988 kg/m³, and at 70 °C – 977.8 kg/m³. For a unit that develops a pressure of 4-6 m of water column and is capable of pumping about a ton of coolant in 1 hour, the difference in the density of the transported medium is 10 kg/m³ (the volume of a ten-liter canister) is simply negligible.
In practice, the difference in static pressure of the coolant in the supply and return lines is equally insignificant.

Hence the simple conclusion: circulation pumps for heating can be installed both in the return and supply pipelines of the heating system of a private house. This factor will not in any way affect the performance of the unit or the heating efficiency of the building.

Boiler room made by our expert Vladimir Sukhorukov. There is convenient access to all equipment, including pumps.

The exception is cheap solid fuel direct combustion boilers that are not equipped with automation. When overheated, the coolant in them boils, since burning wood cannot be extinguished at once. If the circulation pump is installed on the supply side, then the resulting steam mixed with water enters the housing with the impeller. The further process looks like this:

The impeller of the pumping device is not designed to move gases. Therefore, the performance of the device decreases sharply, and the flow rate of the coolant drops.
Less cooling water enters the boiler tank, causing overheating to increase and even more steam to be produced.
An increase in the amount of steam and its entry into the impeller leads to a complete stop of the coolant movement in the system. An emergency situation occurs and, as a result of an increase in pressure, a safety valve is activated, releasing steam directly into the boiler room.
If no measures are taken to extinguish the firewood, the valve cannot cope with the pressure release and an explosion occurs with the destruction of the boiler shell.

For reference. In cheap heat generators made of thin metal, the response threshold of the safety valve is 2 Bar. In higher quality TT boilers, this threshold is set at 3 Bar.

Practice shows that no more than 5 minutes pass from the start of the overheating process to the valve activation. If you install a circulation pump on the return pipe, then steam will not enter it and the time period before an accident will increase to 20 minutes. That is, installing the unit on the return line will not prevent an explosion, but will delay it, which will give more time to fix the problem. Hence the recommendation: it is better to install pumps for boilers running on wood and coal on the return pipeline.

For well-automated pellet heaters, the installation location does not matter. You will learn more information on the topic from our expert’s video:

Installation diagrams in various types of systems

First, let's clarify the place where to install the flow pump, which circulates water through the boiler and forcibly directs it to the radiators of the heating system. According to our expert Vladimir Sukhorukov, whose experience is trustworthy, the installation location must be chosen in such a way that the unit is convenient to maintain. On the supply side, it should be located after the safety group and boiler shut-off valves, as shown in the installation diagram:

In order for the equipment to be removed and serviced, it is necessary to install shut-off valves

On the return, the pump must be placed directly in front of the heat generator, and in tandem with a filter - a mud trap, so that you do not have to buy and install extra taps. The wiring diagram for the pumping unit looks like this:

When installing on the return, 1 less tap is used

Recommendation. A circulation pump can be installed in this way in both a closed and an open heating system, there is not much difference. The statement also applies to the collector system, where the coolant moves to the radiators through separate connections connected to the distribution comb.

A separate issue is an open heating system with a circulation pump, capable of operating in 2 modes - forced and gravity. The latter is useful for homes where power outages often occur, and the owners’ income does not allow them to buy an uninterruptible power supply unit or a generator. Then the device with shut-off valves must be installed on the bypass, and a tap must be inserted into a straight line, as shown in the diagram:

This scheme can operate in forced and gravity mode

Important point. On sale there are ready-made bypass units with a pump, where instead of a tap on the flow there is a check valve. Such a solution cannot be called correct, since a spring-type check valve creates a resistance of the order of 0.08-0.1 Bar, which is too much for a gravity heating system. Instead, you can use a petal valve, but it must be installed only in a horizontal position.

Finally, we will explain how to install and connect a circulation pump to a boiler that burns solid fuel. As mentioned above, it is better to place the unit on the line coming from the heating system to the heat generator, as shown in the diagram:

As you can see, the piping uses a pump connection to the boiler circulation circuit with a bypass and a three-way mixing valve. The important role of these strapping elements is described in detail here.

Installation rules

The design of a household circulation pump from any manufacturer provides for its fastening to pipelines or shut-off valves using union nuts (American). This allows it to be quickly dismantled if necessary, for example, for replacement or repair. When installing the pump unit, follow these recommendations:

Place the device on any sections of pipelines - horizontal, vertical or inclined, but with one condition: the rotor axis must be in a horizontal position. That is, installation “head down” or up is unacceptable.
Please note that the plastic box with electrical contacts is located on top of the case, otherwise it will be flooded with water in the event of an accident. Yes, and servicing the product will not be easy. This is easy to achieve: unscrew the screws securing the casing and turn it to the desired angle.
Remember to follow the flow direction indicated by the arrow on the housing.
So that the product can be removed without emptying the system, install shut-off valves before and after it, as shown in the diagrams in the previous section.

A visual aid showing what position the pump unit should be in

Advice. It so happened that the load from the weight of the circulation unit will fall on 1 or 2 ball valves (depending on the orientation of the area in space). Hence the recommendation: do not save money and buy high-quality shut-off valves, whose body will not crack over time from mechanical stress.

About installing additional units

As a rule, in a closed or open radiator heating system, where the heat source is a single boiler, it is enough to install one circulation pump. In more complex schemes, additional units are used for pumping water (there may be 2 or more of them). They are placed in the following cases:

when more than one boiler installation is used to heat a private house;
if a buffer tank is involved in the piping scheme;
the heating system has several branches serving various consumers - radiators, heated floors and an indirect heating boiler;
the same, using a hydraulic separator (hydraulic arrow);
for organizing water circulation in underfloor heating circuits.

Correct wiring of several boilers operating on different types of fuel requires that each of them have its own pumping unit, as shown in the diagram for the joint connection of an electric and TT boiler. How it functions is described in our other article.

Connecting an electric and TT boiler with two pumping devices

In a circuit with a buffer tank, it is necessary to install an additional pump, because it involves at least 2 circulation circuits - boiler and heating.

The buffer tank divides the system into 2 circuits, although in practice there are more of them

A separate story is a complex heating scheme with several branches, implemented in large cottages with 2-4 floors. Here, from 3 to 8 pumping devices can be used (sometimes more), supplying coolant floor by floor and to different heating devices. An example of such a circuit is shown below.

Finally, a second circulation pump is installed when heating the house with water-heated floors. Together with the mixing unit, it performs the task of preparing coolant with a temperature of 35-45 ° C. The operating principle of the circuit presented below is clearly described in this material.

This pumping unit forces coolant to circulate through the heating circuits of underfloor heating

Reminder. Sometimes pumping devices do not need to be installed for heating at all. The fact is that most electric and gas wall-mounted heat generators are equipped with their own pumping units built inside the housing.

Connecting the circulation pump to the electrical network

There are several ways to connect power to the device:

through a conventional differential machine;
with thermostat control;
connection to the network together with an uninterruptible power supply unit (UPS);
powering the unit from the boiler automation.

Warning. Often, homeowners simply plug the pump into a regular outlet, connecting the wires to a purchased plug. We cannot recommend this approach, because connection without grounding and a safety circuit breaker is dangerous. If there is a problem with the device or if it is filled with water, you risk receiving an electric shock.

Circuit with differential machine

The first connection diagram is quite simple and any user can assemble it with his own hands. You will need an 8 A differential circuit breaker, wires and contacts. Connect to grounding both in this circuit and in all others.

To automatically stop the movement of the coolant when cooling to a certain temperature, an electrical circuit is used to connect a circulation pump with a thermostat. The latter is attached to the supply pipeline and breaks the power supply circuit when the water temperature drops below a set value.

Connecting a phase wire to the pump through an overhead thermostat

Attention! To ensure that the thermostat does not lie and turns off the circulation in time, it must be attached to a metal section of the line. Polymers do not transfer heat well, so when mounted on a plastic pipe, the device will not work correctly.

There are no difficulties in connecting the power supply through a UPS, for which the latter has special connectors. The heat generator itself should also be connected to them if it needs electricity. But connecting the pump to the boiler control panel or to its automation is a more complicated procedure. It is advisable to have knowledge and skills in the field of electrical engineering.

The boiler is also connected to the uninterruptible unit if it needs electricity

At what speed should the pump in the heating system operate?

The purpose of forced circulation is to effectively heat the house through the reliable delivery of heat to all consumers of the system, right up to the furthest radiator. To do this, the pumping unit must develop the required pressure (otherwise known as pressure), which is ideally calculated by design engineers based on the hydraulic resistance of the pipeline network.

Most household pumps have from 3 to 7 rotor speeds, due to which the performance and pressure generated can be increased or decreased. In order not to torment you with hydraulic calculations, we offer the following method for selecting the optimal speed:

Find a laser surface thermometer (pyrometer). Put the heating system into operating mode.
Measure the surface temperature of the pipe at the inlet and outlet of the boiler.
If the temperature difference is more than 20 °C, increase the rotor speed. After 30 minutes, repeat the measurement.
When the temperature difference is less than 10 °C, the water flow rate must be reduced. The goal is to achieve a delta between supply and return of about 15 °C.

3 rotation speeds is the minimum, sometimes 7 or more

Advice. Do not switch the pump to another circulation speed “on the fly”. Disconnect it from the network, move the regulator to a different position, and then put it back into operation.

You can do without a pyrometer when thermometers are installed on the supply and return lines. If the adjustment limits do not allow you to enter the range of 10-20 °C temperature difference, your system is not working efficiently due to an incorrectly selected circulation pump. Too cold return water increases the load on the boiler and increases fuel consumption. Water that is too hot means that it flows too quickly and does not have time to transfer heat to the heating devices.

For reference. The leading European brand Grundfos offers the latest generation Alpfa3 circulation units, which can independently select performance depending on the load and thus adapt the work to changing conditions. With their help, you can even balance the heating system, which our expert will tell you about in the next video:

Conclusion

Now you know exactly how to properly install a circulation pump in a water heating system and connect it to the power supply of a country house. This will save you from making all sorts of mistakes that lead to minor and major troubles. Again, you can install and wire the unit yourself. The only difficulty is to cut it into steel pipelines connected by welding. But there is a way out: find a set of tools for manually cutting pipe threads, cut out a piece of pipe with a grinder and mount the pump unit. The main thing is to have the desire and time to fulfill it.

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How to install a heating pump: instructions

How to install a heating pump

The construction of a private country house usually involves the construction of an individual autonomous heating system. If installed correctly, such equipment will be much more economical and efficient than connecting to the main heating system. In particular, in an autonomous system, the distance that the coolant travels from the place of heating (heating boiler) to the location of heating devices (radiators) is significantly reduced.

An individual heating system can be built either using the principle of free circulation of coolant (hot water flows through pipelines by gravity) or using pumping equipment. In the latter case, the house owner is faced with the question: how to install a heating pump?

Do we need a pump?

Of course, an individual heating system can work perfectly for many years without including pumping equipment. However, the use of circulation heating pumps significantly increases the heating efficiency.

First of all, including a pump in the system reduces the inertia of coolant movement. When hot water moves by gravity, the heated coolant can reach distant heating radiators after a considerable time. As a result, the temperature of the liquid in the pipelines has time to decrease, and the radiators do not heat the rooms as effectively. The difference in coolant passage time can reach an hour or more. Using the pump, all radiators in the house will heat up evenly.
Also, when using a pump, there is no need to build a pipeline system with exact observance of the slope angle. Even if in some part of your house the heating pipe goes uphill, the coolant under the action of the pump will easily overcome this section and air pockets will not appear in the system.

But any technical solution may have its drawbacks.

Electricity in our country is not yet free, so a circulation pump running in the heating system will eat up money from your budget. The power of pumping devices can range from 55 to 100 Watts.
The presence of a pump in the system immediately makes it energy-dependent, so that during any power outage you will have problems with heating.
Stopping the pump may cause excessive heating of the coolant, which will cause rupture of heating circuits or defrosting of remote segments of heating pipelines.

How does circulation heating pump equipment work?

Pump design option

Pumping devices are installed in closed home heating systems. A typical pumping device has a stainless metal housing. The housing houses an electric motor. An impeller is located on the motor shaft; it moves the coolant through the pipes. The design of pumping equipment for heating systems is generally similar to conventional water pumps.

Types of circulation pumping devices

Based on the principle of operation, pumping devices that circulate coolant in heating systems can be divided into “wet” and “dry”.

In a “dry pump”, the rotor of the electric motor, located behind the sealing partition, does not contact the coolant. During operation of the “dry pump”, when the sealing rings rotate, a film of water forms between them, which prevents the coolant from penetrating the engine rotor. Such a pumping device operates with an efficiency of about 80%. The disadvantage of such equipment is increased noise; it is recommended to install it in a separate room.

“Dry” circulation pumping devices can be vertical, horizontal or block type. The type of pumping device affects the technology of its installation and is usually indicated in the technical data sheet of the equipment. In addition, a distinctive feature of “dry” type pumping devices is the need to install them in clean rooms, due to the fact that they are very sensitive to the presence of dust. “Dry” pumps should only be started when there is coolant liquid in the system, otherwise the sealing rings may be destroyed.

"Dry" circulation pump device

In circulation pumping equipment made using “wet” technology, the rotating elements (impeller attached to the rotor) are immersed in a heat carrier liquid. Hot water in this case simultaneously acts as a lubricating and cooling liquid. Such pumping devices are more reliable and unpretentious in operation, but have much lower efficiency - about 50%. Such equipment performs well in domestic heating systems; their efficiency is quite sufficient to create coolant circulation in a private home.

"Wet" circulation pump

Choosing a circulation heating pump

The main criterion for choosing a circulation pump device for heating is its power. It must correspond to the volume of the autonomous pipeline system. Insufficient power will not allow you to effectively use all the benefits of a forced circulation heating system. Excessive power will be a waste of money.

Pump location in the system

In order to calculate the required power of the pumping device, it is necessary to collect the following information:

heating pipeline cross-section;
coolant temperature;
heating boiler performance;
pipeline capacity.

In order not to use complex formulas, the required model of the circulation pump device can be selected according to the output pressure.

The required pressure is calculated using a very simple formula: 0.5 units (meters) of pumping pressure = 10 meters of heating pipeline length.

Installation options for circulation pump devices

Circulation pumping equipment can be installed in a heating system according to two main schemes: single-pipe and double-pipe.

In a single-pipe system there is a constant flow of coolant. The temperature difference in it is not very large.

In a two-pipe system, the coolant flow depends on the operating mode, and the temperature difference of the liquid in the system can reach large values.

Components of the heating system

Heating boiler.
Air valve.
Thermostat device.
Heating radiator.
Balancing valve.
Expansion tank.
Shut-off valves.
Filter device.
Circulation pump device.
Device for measuring pressure in the system.
Safety valve device.

Self-installation of a heat circulation pump

When installing a pumping device, remember that it needs to be serviced from time to time. Therefore, convenient access must be provided to its location. The most convenient location for installing pumping equipment will be the section of the return pipeline (return), located in front of the inlet pipe of the heating boiler.

Such an installation location will ensure that the pump operates with a relatively cold coolant, which will significantly increase the service life of the device. In addition, installing a pump on the return pipe prevents the accumulation of air in the heating boiler tank. This extends the life of the equipment and prevents liquid from becoming trapped in the storage tank.

Algorithm for installing a pumping device

Step 1: Drain the heating system. If necessary, carry out hydrodynamic cleaning of pipelines and heating radiators.

Step 2. An additional pipeline bypass is placed at the selected installation location of the pumping device; it is called a bypass. The purpose of the bypass is to ensure the circulation of coolant in the system when the circulation pump is turned off or broken. The cross-section of the bypass pipeline must be smaller than in the main system.

Step 3. Install the circulation pump device. During installation, it is necessary to orient the pump so that the entire working part (shaft and impeller) is covered with coolant. Remember that running the pumping device dry without load can cause serious damage to the equipment. Also, incorrect orientation of the pump leads to a decrease in its efficiency. The actual power output of the pump may decrease by 30%. You can find a diagram of the correct orientation for your specific pump model in the instruction manual.

When choosing the location of the pumping device and when installing it, it is also necessary to take into account that the terminal box should be located at the top of the equipment. Otherwise, even with a small leak or condensation, it may flood with water. The result is a short circuit.

Step 4. Ball valves must be installed at the inlet and outlet pipes of the heating system pumping device. They facilitate the procedure for dismantling and repairing equipment.

Step 5. Install a water filter in front of the inlet pipe of the pumping device. It will prevent small particles suspended in the coolant from entering the pump. This will significantly delay the timing of repair work.

Step 6. Mount the valve device on the bypass bypass pipeline. It will bleed air pockets if any occur in the system.

Step 7. Treat all joints with silicone sealant. This will prevent leaks from occurring.

Step 8. Fill the heating system with liquid coolant, bleed any air pockets from it by opening the central valve device.

Typically, circulation pump devices in home heating systems do not require regular maintenance. In case of breakdowns, you can contact service center specialists. But in order for your equipment to work without breakdowns, you must follow some rules.

Installation and operation of pumping equipment in individual heating systems does not pose any particular problems. To learn more about this issue, watch the training video.

How to install a heating pump

Heating circulation pumps

Circulation pump device

Installing shut-off valves

Insertion diagram of a heating pump device

Pump design option

Orientation of the pumping device

Two-pipe heating system

Pump location in the system

Single-pipe heating system

How to connect heating radiators in a private house

The heating pump is installed in accordance with the manufacturer’s instructions, which describe in detail the installation process of this equipment. In practice, several methods of arranging pumping units in the heating system of a private house have been tested. In each case, the owner of the facility selects the most suitable option, taking into account the type of boiler and expansion tank used, the type of heating system, and the presence of additional elements.

Selecting the right unit

When choosing a circulation pump for an autonomous heating system, they are guided by two main criteria - unit performance and pressure. The first of these parameters characterizes the volume of coolant that the unit can pump over a certain period of time, and the second indicates the height to which the pump can lift the liquid. In addition, you need to consider:

The cross-section of pipes to which the circulation pump will be connected.
Dimensions of the space allocated for installation of the pumping unit.
Maximum coolant temperature.
Power and throughput of the heat generator.
Volume of heated premises.

We have already talked about the classical calculation method in the article. At the same time, there is a simpler method that can be used both for preliminary calculations and for checking the results of more thorough calculations. It is based on the requirement that the circulation pump must pump three times its filling volume through the heating system in one hour of operation.

The last value can be indirectly estimated from the power characteristics of the boiler. If the thermal unit was selected according to the rules, then for every kilowatt taken from its technical data sheet there are at least 15 liters of coolant. It is enough to multiply the power of the heat generator in kW by 15 and make a correction of 20% in order to estimate the filling of the heating circuits with sufficient accuracy. After the volume of coolant has been calculated, it will not be difficult to calculate the required performance of the circulation pump in l/min - to do this, the filling of the circuits in liters must be multiplied by three and divided by sixty. If we take a heating system with a 15 kW boiler as an example, we can assume that the volume of liquid in all its branches is approximately 270 liters (Q = 15 kW x 15 l + 20%). For forced circulation of coolant, you will need a pump with a flow rate of at least 0.81 m 3 / hour or 13.5 l/min.

The required pressure value of the circulation pump can also be determined without going into complex mathematical calculations. To do this, you can use the formula N = X * K, where X is the number of floors of the building, including the basement, and K is a correction factor equal to 0.7-1.1 for traditional two-pipe heating schemes and 1.2-1.85 for collector-radial circuits. So, if you calculate the hydraulic resistance of a collector heating system of a two-story building with a basement (the number of levels is three), then you will need a pump with a pressure of 3x1.85 = 5.55 m.

The obtained values will already be enough to decide on a specific model of a circulation pump from any manufacturer. To do this, the operating point is found on the graphs of the hydraulic characteristics of centrifugal units - it is located at the intersection of the segments drawn from the abscissa (performance) and ordinate (pressure) axis. The best position of the operating point is considered to be the middle third of the graph, which corresponds to the maximum efficiency.

The graph of the hydraulic characteristics of the circulation pump allows you to analyze whether the unit meets the requirements for pressure and performance

To obtain a sufficient reserve in both directions, you should focus on the curve constructed for the average speed of the circulation pump. In this case, it will be possible to reduce its power if there is excessive noise or increase it if the coolant at the entrance to the boiler has an unacceptably low temperature.

Features of the design of a heating system with pump circulation are studied in this article:

Determining where the pump is inserted into the system

When installing a circulation pump, it is necessary to take into account not only the manufacturers’ recommendations, but also the possibility of its periodic maintenance. More recently, it was recommended to install pumps with a “wet” rotor exclusively on the return line - it was believed that this way they would work much longer, since they would be in a more gentle temperature regime.

Typical diagram for connecting a pump providing forced circulation of coolant to an autonomous heating system of a private house or country cottage

Modern units are designed for long-term contact with hot liquid, so they can be safely installed on the supply side. Moreover, experts often recommend installing the pump on the supply pipeline in order to increase the pressure in the suction zone. In this case, the specified area will have the highest temperature, so you must make sure that the electrical device is capable of contact with high-temperature liquid. The advantages of this method can be appreciated, for example, by owners of warm water floors, since in this case the formation of air pockets is eliminated.

For heating systems with membrane tanks, on the contrary, it is recommended to install a bypass with a pump on the return side, closer to the expansion tank. If such a scheme makes it difficult to service the pump, then it is cut directly into the main line, always equipping the circuit with a check valve.

Choosing a circulation pump and deciding where to install it is only half the battle. It is equally important to carry out the piping correctly - only in this case can you count on long, trouble-free operation and the possibility of comfortable servicing of the unit. There is nothing complicated in the recommendations of experts:

The pump installation location should be equipped with ball valves. With their help, it will be possible to isolate the unit from the coolant during preventive or repair measures.
On the coolant inlet side, it is necessary to install a coarse filter, which will serve as a barrier to mechanical particles. As practice shows, the presence of such a device slows down the process of abrasive wear of the impeller several times. If we talk about the danger of damage to the pump, then the importance of filtration is difficult to overestimate.
The uppermost point of the bypass should be equipped with a venting valve.
The direction of movement of the coolant must coincide with the arrow on the device body.
Since in “wet” type pumps cooling and lubrication is performed by the pumped coolant, the axis of rotation must be parallel to the horizontal.
To ensure tightness, mating parts and their joints are sealed using gaskets and sealants.

It is equally important to correctly connect the pump to the electrical network. The type and cross-section of the cable must correspond to the power of the unit, and the connection must be made only with protective grounding.

Basic installation rules

Options for correct and incorrect placement of a circulation pump with a “wet” rotor. It is strictly prohibited to place equipment as shown in the bottom row.

The need for water filtration

Important! Most filters are equipped with an arrow indicating the correct direction of water flow in the circuit. If you ignore the direction of the arrow, you will have to clean the mud pan much more often.

Pump location in the heating circuit

One of the options for correctly inserting a circulation pump into the pipeline of the heating system of a private house with a circuit length of no more than 80 meters

Why is bypass needed?

The circulation pump is installed on, which is cut off from the main system using two ball valves. This placement of the equipment allows it to be repaired or replaced without damaging the heating system of the house. In the off-season, the heating system can operate without a pump, which is shut off using the same ball valves. When frost intensifies, the pump is put into operation by opening the shut-off valves along its edges and closing the ball valve on the main circuit. This is how the direction of coolant flow is adjusted.

Installation of the circulation pump on the bypass (bypass pipe) using three ball valves ensures the coolant flow in the desired direction

Electrical connection

Connecting the pump to an uninterruptible power supply (UPS), which is additionally reinforced by three battery units connected in series into a single circuit

The following material will help answer the question of why install a circulation pump:

Checking operation and putting it into operation

After reading the instructions and reading this article, you can carry out the installation work yourself. If you do not understand how to install a heating pump, then invite a professional technician.

The circulation pump increases the efficiency of the autonomous heating system and makes it possible to use all heating circuits 100%. Professional installation of a pump in the heating system of a private home allows you to reduce repair and maintenance costs, as well as reduce operating noise and guarantee more efficient performance.

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General information

Until relatively recently, circulation pumps were used only in centralized heating schemes, and for private houses the natural movement of the coolant due to temperature differences was considered the norm. Today, forced circulation is used almost everywhere thanks to the advent of small and inexpensive devices that are designed specifically for servicing the heating system of private cottages.

By increasing the speed of movement of the coolant in the pipes, heat flows faster to the radiators, and accordingly, all rooms are heated almost instantly. The load on boiler equipment is reduced, since heating of the liquid also occurs faster.

Installation of a GRUNDFOS circulation pump in a heating system. Bypass installation

There is no longer any need to connect inconvenient and bulky large cross-section pipes. It has become easier to hide contours under the floor covering.

The main disadvantage of circulation pumps is their dependence on electricity. If the electricity supply is intermittent, then installation of a backup power source is required. The remaining disadvantages relate to the functionality and design of devices of various types. For example, monoblock and rotary pumps are noisier and require regular maintenance, while a pump with a wet type of operation is more demanding on the quality of the coolant.

Types of pumps

Based on their design features, all pumps are classified into two main groups: dry and wet rotor. For private houses, it is best to connect the pump to a wet-type heating boiler. It is small, almost silent and easy to maintain, but it does not have very high performance: efficiency is no more than 55-57%.

Devices with a dry rotor are more powerful, unpretentious to the quality of the coolant, can operate under high pressure, and are installed vertically. But they are quite noisy and vibrate a lot. Most pumps are mounted on a foundation or a support frame on the wall.

To install “In-line”, monoblock or console devices, there must be a special room - a boiler room. They are most often installed if the hot coolant circulates more than 120 m³/h, that is, these pumps are required to service multi-story buildings.

Pump. Feed or return? Where to put it correctly. Answers to questions

Main Features

When choosing a pump, it is necessary to study the technical parameters, comparing them with the requirements of the heating system.

The main criteria are:

productivity - the volume of coolant or pumping over a certain period of time;
pressure that covers hydraulic losses in the pipeline;
power;
operating coolant temperature.

Structural elements are also important, for example, the diameter of the inlet and outlet pipes. For heating systems, approximate parameters will be 25−32 mm.

Devices with built-in electronics make it possible to quickly switch the system to a more convenient mode, taking into account changes in temperature or pressure in the circuit. Automatic pumps are equipped with digital screens that provide information about the operation of the device.

Installation rules

There are certain norms and rules that describe at the legislative level where and where it is correct to install the circulation pump. The main part is regulated by SNiP 2.04.05. Almost all rules are based on the operating efficiency and performance of the heating system as a whole, including the pump. For example, the shaft of wet-type equipment must be cut into the pipeline clearly horizontally so that no air pockets appear inside.

A coarse filter must be included in the heating circuit even during the installation of monolithic models. The filtered coolant will cause much less damage to all pump elements than contaminated water.

Certain rules are specified by equipment manufacturers. For example, until relatively recently, some models of the old pump group could only be installed on the return line, since these pumps could not withstand elevated temperatures. Today, pumps are universal in nature and the location of this equipment can be done at any convenient site.

The pump itself can be installed both vertically and horizontally; only when choosing a device you need to make sure that the equipment can operate in both positions. You also need to take into account one nuance: during vertical installation, the power is reduced by approximately 35%. This must be taken into account when choosing a device.

Heating diagram Connecting batteries and heating radiators Single-pipe two-pipe heating system

Fastening schemes

When choosing one of the schemes for how to properly install a pump for heating a private house, you must definitely take into account ease of maintenance, the type of boiler and the type of heating system.

The first method is the most popular: the pump is installed on the return line, through which cold coolant is supplied to the boiler. Cool liquid does not act so aggressively on all elements of the device, so the equipment can last longer.

The second method is used if, for certain reasons, it is impossible to install a pump on the return line. In this case, it is fixed at the beginning of the circuit, but not near the boiler itself, but behind the safety group.

Another option for the heating system is when an expansion tank is installed at the highest point of the circuit. If you additionally install a pump, it will be possible to operate the system in two modes - forced and natural. In this case, you can choose which method to use in each specific case.

The last scheme can only be applied to systems with a solid fuel boiler. The pump is not installed on the supply pipeline due to the possibility of explosion. It’s just that with boilers of this type it is impossible to instantly stop the fuel combustion process, as a result of which the coolant begins to boil.

Hot liquid simultaneously with steam penetrates inside the pump unit, which reduces performance. The cold coolant in the circuit does not have time to flow back into the boiler in the required volume, and the boiler begins to heat up even more. The consequence of overheating is an explosion.

If cold liquid is supplied to a heating boiler from the circuit, condensation will form. To prevent this from happening, the water is first heated in the small circuit to +50 degrees, and then the thermostatic valve smoothly transfers the liquid to the large circuit. This way, the cold coolant mixes with already heated water, and boiling does not occur.

Tying methods

Piping is equipment that is required for the proper operation of the pump unit, as well as for the smooth functioning of the entire heating system.

First you need to finally decide how many pumps will be installed. For one circuit, one device is sufficient, but for a complex circuit it is better to install two or more.

If you plan to install a heated floor or use a boiler, then it is advisable to increase the number of units to two. If there are two boilers in the house, then separate pumping equipment will also be needed for each of them.

Ball valves are required for installation in the heating system. They are installed simultaneously with the pumping unit. A check valve is also required so that the coolant moves in one direction. The valve is installed on the pipe immediately after the pump in the direction of fluid movement.

Installing a circulation pump

It is necessary to install a coarse filter to prevent sand and dirt from entering the device body. Fine filters are not installed in the heating system. If purified water is required, it is pre-cleaned before pouring into the boiler.

There is a risk of air entering the system, so it becomes necessary to install an air valve that can turn on automatically. There are also manual options.

After installation of the equipment, an electrical connection is required. Do not connect to a regular outlet without grounding. This is a gross violation of safety regulations, which during an emergency can lead to dire consequences.

There are smarter connection options:

using a boiler connected to automation;
differential circuit breaker;
uninterruptible power supply.

It is best to use a circuit breaker. To do this, you need an 8 A switch, contacts and cables. If you plan to use a UPS, you can simultaneously connect it to both the pumping equipment and the boiler.

When connecting equipment to electricity, it is necessary to exclude the possibility of condensation entering the terminal box. Heat-resistant cable is used if the thermal fluid in the heating system heats up more than 95 °C. It is prohibited for the cable to come into contact with the pump housing, electric motor, or pipe walls.

Installation instructions

Correct installation of the circulation pump in the heating system is carried out using a bypass. This is due to several reasons: this way you can quickly dismantle it or temporarily disconnect the device from the network, for example, when problems with electricity arise.

There are different models of ready-made pump units on sale - for flange mounting or welding, with areas for mounting valves or taps, with additional space intended for a pump. But if it is impossible to buy a ready-made unit or there is no place to install it, then you can make the bypass piping yourself and secure all the elements.

To work you will need:

pliers;
set of keys;
sealant;
tow.

American nuts, as a rule, are included with pumping equipment, but drives, adapters and taps must be purchased in advance. Attention should be paid to the quality of the material and the diameter of the products.

How to install the pump?

Installation steps:

The pump unit is serviced in operating mode. It is necessary to regularly clean the filter and monitor the pressure gauge readings. If the readings do not correspond to the norm, the device must be dismantled and its position adjusted.

After installation work is completed, the heating system is filled with water. Then the air is removed using the unscrewed central screw, which is located on the housing cover. The appearance of water indicates complete removal of air pockets from the heating system. The pump can then be turned on.

As practice shows, most home craftsmen are quite capable of installing a circulation pump with their own hands. But when difficulties arise, it is better to seek help from professionals, since only experienced specialists know how to properly tie and install pumping equipment, observing all the nuances of the heating system.

For owners of country houses with individual heating systems, the issue related to the uniform distribution of heat between all rooms is particularly relevant. For this purpose, circulation pumping units are used. And the question immediately arises: how to install a heating circulation pump so that it ensures uninterrupted, highly efficient, reliable operation? In this article we will look at this issue in detail.

Reasons for installing a circulation pump

A standard problem for owners of private houses is the uneven distribution of heat throughout the heating system. If in distant rooms the radiators are lukewarm, but the boiler boils, then you have to look for methods to improve the efficiency of the entire heating system.

To distribute thermal energy throughout the house, the following solutions are most often used:

increasing the diameter of the heating system pipes;
installing a pump in a heating system that is already present.

The first method is effective and practical, but it requires significant financial and physical costs, since you will have to dismantle all the old pipes and replace them with new ones. Installing a circulation pump in the heating system will not only ensure the same temperature throughout the house, but will also prevent the occurrence of air locks, which are the cause of poor coolant circulation. In addition, the cost of installing a small pump is much lower than replacing the pipes of the entire heating system, and much less physical effort is also required.

Design and principle of operation of the circulation pump

Circulation pumps are designed for forced circulation of warm water in closed heating systems. The pump consists of a stainless steel body and a steel rotor or motor screwed to it; an impeller is attached to the motor shaft, which contributes to the release of the coolant. The operation of the pump is driven by an electric motor. A pump installed in a heating system draws water from one side and throws it into the pipeline due to the centrifugal force that occurs when the impeller rotates. The pressure created by the pump must easily cope with the hydraulic resistance of the pipeline, radiator and other elements of the system.

Types of circulation pumps

Typically, heating pumps are divided into two types:

"wet";
"dry".

In “dry pump” designs, the rotor does not interact with the coolant; its working area is separated from the electric motor by special stainless steel sealing rings. When started, these rings begin to rotate one towards the other and a thin film of water located between the rings seals the connection due to different pressure levels in the heating system and the external environment. The efficiency of a circulation pump with a dry rotor becomes 80%. In addition, it is quite noisy compared to a “wet” pump, so it should be installed in a separate, well-soundproofed room.

In turn, “dry” pumps are divided into three types: vertical, horizontal and block. For horizontal “dry” circulation pumps, the suction pipe is located on the front of the shaft, and the discharge pipe is located on the housing. The electric motor is mounted horizontally. For vertical pumps, the pipes are located on the same axis, and the electric motor is located vertically. Warm water enters the block pump along the axis and is discharged radially. When operating a “dry” pump, the dustiness of the room should be monitored, as it can cause turbulence of dust and other small solid particles, which can damage the surface of the seal rings, and as a result, the tightness of the pump. It is worth remembering that a “dry” pump requires the presence of liquid as a lubricant, since its absence significantly increases the risk of destruction of the mechanical seal.

“Wet” circulation pumps differ from “dry” ones in that the rotor and impeller are immersed in a coolant, which simultaneously acts as a lubricant and coolant. The rotor and stator are separated by a special “glass” made of stainless steel, which ensures the tightness of the part of the electric motor that is energized. For a heating system, the body of the “wet” pump should preferably be bronze or brass, and the rotor should be ceramic. Compared to “dry” pumps, wet ones are less demanding in maintenance and repair, and in addition, they are much less noisy. However, there is also a minus: the efficiency of a “wet” pump is about 50%. This is due to the fact that it is almost impossible to seal the sleeve that separates the coolant and the stator. “Wet” circulation pumps are mainly used in domestic heating, since such performance is quite sufficient for short-length heating systems.

How to choose a heating circulation pump

The first thing you should pay attention to when choosing a circulation pump is its power. It is worth remembering that for high-quality heating it is not necessary to choose a large pump with too high power. It will only create unnecessary noise, cost much more, and there is no need for it as such.

To choose a heating device, you should make an accurate calculation of the power of the circulation pump that is optimal for your home. To do this, you need to know the following parameters: pipe diameter, water temperature, coolant pressure level, throughput and boiler performance.

It is important to know how many liters of water can pass per minute through the heating system (boiler power). In addition, it is necessary to calculate the amount of water required for the normal operation of the radiator and heating system rings.

The power of the circulation pump also directly depends on the length of the pipeline. As a rule, approximately 0.5 m of pumping head is required per 10 m of pipeline.

To calculate the coolant consumption, you simply need to equate it to the boiler power parameters. For example, if the boiler power is 25 kW, then the coolant flow is 25 l/min. Batteries with a power of 15 kW require 15 l/min of water. It is also worth remembering that the narrower the pipeline, the greater the resistance that will arise along the path of movement of the coolant.

Calculation of circulation pump flow for heating

Any circulation pump has a number of indicators, which determine its performance. The main ones are pressure and flow. These parameters are reflected in the technical data sheet.

The flow rate of the heating circulation pump is calculated using the formula:

where N is the boiler power; t1, t2 is the temperature leaving the heat source (in most cases - 90-95 degrees) and in the return pipeline (usually -60-70 degrees), respectively.

The pressure of the heating pump is calculated in the same way; according to European standards, 100 W of power is required for 1 sq.m. of private house area.

Circulation pump installation diagrams

There are two typical installation schemes for a circulation pump: single-pipe, double-pipe.

The first scheme is characterized by a constant coolant flow rate and a small temperature difference, while the second, on the contrary, is characterized by a variable flow rate and a high temperature difference.

The following figures show connection diagrams for the heating circulation pump, where: 1 - boiler, 2 - automatic air vent, 3 - thermostatic valve, 4 - radiator, 5 - balancing valve, 6 - expansion tank, 7 - valve, 8 - filter, 9- circulation pump, 10-pressure gauge, 11-safety valve.

Installing a circulation pump - stages and important installation nuances

Before installing the circulation pump, carefully study the instructions and its connection diagram. It is important to take into account the fact that the heating system will need to be serviced from time to time, so it must be taken care of.

First, you should drain all the heating fluid from the system, then, if necessary, clean the pipeline. Installation of the pump and the functional chain of fittings is carried out according to the connection diagram. Upon completion of installation, the heating system is filled with water, then excess air is removed from the pump by opening the central screw. It is worth paying attention that the air should be removed before each time the circulation pump is turned on.

After the heating circulation pump has been purchased, we begin to determine its installation location. It is recommended to install the circulation pump on the return line, in front of the boiler. The thing is that air can collect at the top of the boiler over time, and if the pump is installed on the supply, it will seem to pull it out of the boiler, as a result of which a vacuum can be created, which will lead to boiling of this part of the boiler. If the pump is placed in front of the boiler, the coolant will be pushed into it, as a result of which no air space will be created and the boiler will be completely filled. In addition, with this installation, the circulation pump will operate at lower temperatures, which will increase its service life.

At the selected pump installation site, a so-called bypass (bypass) is performed. It is necessary so that in the event of a pump breakdown or a power outage, the entire heating system does not stop working, and the coolant passes through the main pipeline thanks to open taps. It should be remembered that the diameter of the bypass pipe must be less than the diameter of the main pipeline. After the bypass is ready, proceed to installing the circulation pump.

It is important to remember that the shaft of the circulation pump must be installed horizontally, otherwise only part of it will be in the water, that is, the pump will lose about 30% of its performance, and in the worst case scenario, the working area may malfunction.

In addition, the installation also provides for an upper location of the terminal box.

Install ball valves on both sides of the pumping equipment. You will need them in the future for maintenance and dismantling of pumping equipment.

The system must necessarily include a filter, which is designed to protect the mechanism from small mechanical particles that can cause significant damage to the pump.

A manual or automatic valve should be installed on top of the bypass pipeline line, which is necessary to release air pockets that arise after a certain period.

To prevent arbitrary water flow in the heating system, it is necessary to secure shut-off valves in the pump inlet-outlet area.

When attaching the motor shaft, it is necessary to ensure that the box rotates along the axis with minimal effort. For an open heating system, it is also necessary to provide an expansion tank.

The connecting nodes should be treated with sealant, which will increase the performance of the entire heating system

To make the pump installation process easier and to avoid the need to search for connections and fasteners yourself, find in stores a special device with already selected detachable threads.

The number of circulation pumps required depends on the length of the pipeline. For example, if the length of the pipe is about 80 m, then installing one pump will be sufficient, but if the length exceeds this figure, then it is necessary to use two or more heating circulation pumps.

The cost of installing a heating circulation pump fully depends on the model of the equipment itself, the complexity of the bypass pipes and, of course, the number of pipeline circuits.

Causes of failure of heating circulation pumps

The most common causes of failure of heating circulation pumps:

incorrect pump installation

The motor shaft must be positioned strictly horizontally, otherwise air may accumulate in the pump, which will damage the device.

Incorrect terminal module position or cable routing
ignoring the pump bleeder procedure
Poor quality cleaning of the system from solid particles

It is worth remembering that all circulation pump malfunctions require specific skills and knowledge, so it is better to entrust the repair of heating equipment to professionals.