Do you hear thuds, noise, crackling when the boiler heats up?
Lost hot water pressure in the kitchen and shower?
Most likely your boiler is clogged with scale and needs to be cleaned urgently.
You can order boiler flushing services from a third-party organization, or you can do it yourself.
How? Read our article!
What is the danger of scale and hardness salts for the boiler?
The main problem is that scale can completely clog the boiler coil. Water will stop flowing and costly repairs will be required.
On the other hand, scale has a low thermal conductivity compared to metal, and therefore causes excessive gas consumption. At the same time, the boiler begins to consume 10-30% more fuel.
In addition, scale causes metal aging, so there is a risk that the boiler coil may burst and create an emergency. And this is fraught with defrosting of the heating system. What is it - read in Yandex.
Why and at what temperature does scale form in the boiler?
Scale is formed because when the water is heated above 60-80C, the hardness salts contained in it (mainly Ca and Mg salts) decompose into carbon dioxide and insoluble sediment. This sediment is deposited inside the boiler, gradually making it unusable.
How to remove hardness salts from water?
Hardness salts harmful to the boiler can be removed from the water by using various filters or water treatment plants.
To select filters, first of all, you need to do a chemical analysis of water, which must contain data on:
- Hardness of water;
- The amount of iron;
- Dry residue;
These are key factors. Water hardness is scale, iron is rusty stains on plumbing (sometimes not removed by anything). Dry residue - the amount of suspended particles in water.
To combat the hardness of water, it is softened - filters are used to soften (desalinate) water. Iron is removed by iron filters, suspended particles are retained by mechanical filters.
Filters for softening water work due to.
In the picture: household filters for mechanical cleaning and removal of iron in a country house
The composition and capacity of the water treatment plant depends on the initial water quality and the planned consumption volume. For the calculation of these indicators, it is better to contact a water treatment specialist.
Scale in a gas boiler symptoms
However, it is not always possible to completely remove hardness salts from water. Good water treatment is very expensive. Therefore, always monitor the following boiler performance indicators:
1. Sound during boiler operation. When contaminated, the boiler begins to make dull sounds, crackle when heated.
2. Increase in gas consumption.
3. Increasing the time for heating water to the required temperature.
3. A sharp drop in water pressure in the taps. The reason for this may be a decrease in the flow area in the boiler.
If these signs are present, immediately flush the boiler from scale! Remember that if the flow of water through the boiler is gone, in 99% of cases this is a major overhaul.
How often do you need to flush boilers from scale?
We do not know what kind of water treatment is installed in your house. Therefore, the main recommendations are:
1. If there is no water treatment at all and the water comes from a well. Flushing the boiler - at least once / twice a year! Although sometimes this is not enough.
2. If there is water treatment, wash every two years. Preferably. This is the average time between flushes.
In any case, watch how the boiler works!
How to flush a gas boiler from scale?
In addition, the topical issue is the choice of a chemical reagent. Again, on the Internet, there are many tips to use household products for chemical washing of boilers. Vinegar, anti-scale, anti-rust, soda, Coca-Cola, Sprite and much more ... What can I say? We tried, it doesn't work. At least for the serious amount of scale that accumulates in the coils and heat exchangers of boilers. Of course, Coca-Cola contains a small amount of phosphoric acid, which is used in industry, including for descaling. By the way! Once again, we warn you about the dangers of drinking such drinks! Dissolves the tissues of the gastrointestinal tract (together with the teeth) - easily. So, Coca-Cola, Sprite can be boiled in a kettle and in some cases the white limescale will be removed. However, this does not always happen, and this plaque is not at all what is formed in the boiler ...
Other cleaning agents: hydrochloric, sulfuric, nitric, phosphoric - all these acids are used in industry, however, we would not recommend using them in everyday life. These acids are very strong, their vapors are poisonous, and serious precautions are required when handling them. In addition, some of them are simply not sold to private individuals because they are hazardous chemicals.
In our practice, we use formulations based on sulfamic acid. We ourselves develop a formula for a detergent that contains, in addition to the main active ingredient, corrosion inhibitors. They prevent chemical corrosion of the metal from which the washed equipment is made.
Sulfamic acid belongs to the 3rd class (substance moderately dangerous), it is supplied in bulk form, therefore it can be transported without any restrictions.
The good thing is that sulfamic acid is a universal remedy that effectively removes carbonate scale (hardness salts - Ca, Mg), as well as rust.
We have developed a detergent for washing boilers and we package it for individual use. Packing - from 1 kg. The cost of 1 kg. detergent - 280 rubles. Is it a lot or a little? One kilogram of detergent (supplied in powder form) is enough to wash the boiler, the water volume of which is up to 15 liters. In our opinion, 280 rubles is a penny, given that the cost of a heat exchanger or a boiler coil is in the thousands of rubles. Therefore, call us at +7 (495) 726-96-98 and we will supply you with detergent as soon as possible!
On our website you can find useful materials on the use of sulfamic acid.
On this page: , you can learn more about this substance and the technology of its use - concentration, temperature and other parameters.
Gas boiler flushing pump
1. Assemble the flush circuit yourself. For this, as we have already said, you will need: an expansion tank (its volume should be 3 times less than the volume of the boiler being washed), a pump, hoses.
2. Buy mobile equipment for washing boilers and heat exchangers. This equipment is a single unit in which a pump with hoses (forward and return lines) is mounted on the expansion tank. Ideal tool, equipment. Specially designed for chemical cleaning of boilers. Models differ in the volume of the expansion tank, and, accordingly, in cost. For the house, the younger model is quite enough - for 15 liters. For larger boilers - count. It is desirable that the volume of the expansion tank exceed the volume of the coil by 2-3 times.
You can buy these pumps from us at the lowest price, since we are dealers supplying Italian equipment. The minimum cost of a pump with an expansion tank of 10 liters is 45,000 rubles.
Pictured: professional chemical pump with 14 liter tank
3. Rent of a chemical pump. In principle, we can provide you with a chemical pump for rent, teaching you all the rules for flushing. Sometimes this is the preferred option because, as you have seen above, chemical pumps start at $45,000.
Renting a chemical pump for 15 liters costs 5,000 rubles per day. Why per day? Just this time is enough to flush one boiler. As a rule, the washing cycle lasts 3-4 hours.
Procedure for flushing a gas boiler
So, you have decided what to wash, so then we perform the following sequence of actions.
1. We turn off the washed object. In Russian - we turn off the taps that supply water to the boiler and at the exit from the boiler. Ideally (and this should be taken into account at the design stage!) so as not to suffer with the connection later, two ball valves should be provided at the inlet and outlet of the boiler, to which a chemical pump can be easily connected.
One smart person, for example, did this:
In the picture you can see two groups of taps and one tap on the side (safety valve). For flushing, the lower two taps are closed (direct, return), and the pump is connected to the upper two taps. Everything! Elementary and brilliant! Connection - 5 minutes. And there is no need to drain the water from the 50 liter boiler, which is already hot and ready for use ...
Pictured: AEG 50 boiler shown
So, if you have taps for flushing, connect a pump to them, if taps are not provided, look. As a rule, on wall-mounted boilers, the supply and return must be disconnected. Be careful, sometimes installers do everything so back-to-back that pipes and connections can be damaged, especially if they are plastic. I hope you remember to turn off the water supply before disconnecting the pipe!
On floor-standing boilers, at the bottom in the back of the boiler, as a rule, there is a drain (drainage) where you can connect the return, and the boiler has a safety valve with a pressure gauge where the supply hose is connected.
See, for example, how this is implemented on the Viessman Vitogas 050 boiler:
Be careful, the system works under pressure, therefore, first of all, stop the pumps, shut off the direct and return lines, release the pressure, and only then start connecting.
So, in the end, you should end up with this:
In the picture you can see how the chemical pump is connected to the boiler being flushed.
By the way, why is the pump higher than the boiler? The fact is that when one person works and the capacity of the expansion tank is only 14 liters (against 67 liters of water in the boiler), you have to be very careful to keep the expanding liquid within the expansion tank. And the pump with a tank installed above the boiler helps in this ...
We check the tightness - pour water into the expansion tank of the pump and turn on the pump, until there is no chemistry. We look at how it works, whether it flows at the connection points.
Preparing the cleaning solution
Detergent (powder or liquid concentrate) is poured into the expansion tank gradually, in accordance with the recommendations for preparing the solution. When it comes to sulfamic acid, we recommend using a 5% solution at around 60°C. Those. for 10 liters of water you pour 500 grams of sulfamic acid or detergent (if you bought from us). Attention! During the reaction, carbon dioxide is released, which squeezes water out of the boiler. That is why we said that the intermediate tank should be larger than the volume of the boiler being flushed. Therefore, pour gently, let the powder gradually stir, and you will control the process of gas formation.
You can judge the effectiveness of the reaction by the gas that will be released into the intermediate tank, foam will form, the wash solution will darken and become cloudy.
Keep track of these metrics. In principle, you can increase the temperature to 60°C (but no more, otherwise the acid will hydrolyze and the effectiveness of the chemical wash will decrease) and bring the concentration of the solution to 10%. Don't worry, nothing will happen to the boiler, especially if you use our detergent. Watch out for external parameters. Dilute the acid gradually. Warm up slowly. In our practice, it also happened that we overheated the boiler, and then boiling acid whipped in all directions. Not particularly dangerous, but annoying.
By the way, about gases. In order to squeeze out the gases accumulating in the upper part of the boiler, which are formed during the reaction of the flushing liquid with scale, we practice periodic shutdown of the pump. This creates a small water hammer (it’s not scary for a washed coil, since in such pumps the maximum pressure does not exceed 2 atm) and the air is gradually pushed into the expansion tank. Those. during flushing, we stand nearby, look at the liquid level in the expansion tank and periodically turn the pump on and off.
Security measures
Of course, when working with acid, be careful. We use sulfamic acid as the safest for humans, but it is necessary to work with goggles, a respirator and gloves. Take care of your eyes, respiratory organs! During the reaction, a gas is released that has a characteristic odor, and which is useless to inhale without a respirator ...
How long does it take to flush the boiler?
As a rule, flushing of household boilers takes 2-4 hours, depending on the degree of contamination.
You can judge the effectiveness of flushing by the following signs: the appearance of foam, cloudiness of the solution, an increased pungent odor, an increase in the amount of solution in the expansion tank.
These signs indicate the presence of a reaction, and hence the dissolution of scale.
During washing, the temperature should be maintained at about 50-60 ° C, to monitor the acidity of the washing solution.
Oh, by the way, about measuring pH. It is advisable to buy test strips for measuring acidity with indicators from 1 to 14 units (the most acidic and most alkaline medium). During the reaction, a gradual decrease in the acidity of the solution occurs, the color of the indicators shifts from dark red to yellow (in the direction of a neutral solution).
Neutralization
When you finally finish flushing your boiler or heat exchanger, you will need to neutralize the flush solution. To do this, stock up on ordinary soda.
Or you pour all the washing solution into a separate container, call the Ministry of Emergency Situations, and they take the solution to the MSW landfill (just kidding). Or you start adding a little soda to the intermediate tank. The pump is running. Soda will react with acid, hiss, neutralize the latter. At the same time, you measure the pH, and as soon as it reaches 6-7 units (neutral), this solution can be drained into the sewer. It is desirable, at the same time, to add cold water to the intermediate tank and drain the solution with a temperature of less than 50°C. These are the regulatory requirements of one of the RD (guiding document) dedicated to chemical washing. By the way, you need to find this document ...