Periodic flushing of the gas boiler heat exchanger is a basic requirement for the maintenance of heating equipment. Cleaning significantly affects the smooth operation of the entire system and greatly extends the life of the home heating device. When should I flush and can I do it myself?
During the operation of a gas boiler, a layer of scale forms, which prevents the necessary cooling of the heat exchanger. In this case, the circulation pump takes on a large load. Therefore, without flushing the heat exchanger, the heating unit may fail.
At home, cleaning should be done every two years. If the water in the house is hard enough, then it is recommended to reduce the interval between flushing.
The first signs for the user that the heat exchanger needs to be flushed are:
- prolonged heating of the gas boiler;
- decrease in heat output;
- partial heating of the system;
- the presence of extraneous sounds during the operation of the heater;
- significant increase in gas consumption.
When scale appears in double-circuit boilers, the water may not completely warm up or the pressure level may decrease.
It is advisable to avoid the combination of such symptoms. But if there are warning signs, flushing should be done immediately.
In addition to the internal cleaning of the heat exchanger, external cleaning of its body from soot is used. Socialized services are engaged in the elimination of scale and pollution in the gas boiler system. Their services are not cheap. Therefore, sometimes you can flush the heat exchanger yourself.
Heat Exchanger Flushing Methods
The method of cleaning the heat exchanger in a gas boiler depends on the design of the device itself and the quality of the water used in the heating system. A booster is used for a complete flush. With such special equipment, you can clean the heat exchanger inside without disassembling it.
Flushing can be done independently with or without a booster. There are three main methods for flushing a gas boiler. Each option has its own characteristics.
Manual cleaning
Observing all safety measures, the heat exchanger can be cleaned independently at home using manual flushing.
This process can be done in two ways:
- Mechanical cleaning. Cleaning of blockages and scale from the heat exchanger is carried out with tools such as a brush, a wooden hammer or a metal brush.
- Washing with active solutions. This option is most effective, especially for boilers with two circuits.
For severe blockages, two types of cleaning can be used - washing with a solution, and then mechanical cleaning.
At home, removing dirt and scale from the heat exchanger is quite simple. First you need to shut off the gas supply, turn off the power supply and disassemble the boiler:
- remove the door (cover) of the boiler by unscrewing all fasteners;
- disconnect all wires from the gas valve;
- disconnect the wire from the piezoelectric element;
- remove the nozzles, thermocouple and unfasten the gas supply pipe;
- remove the burner from the appliance;
- open the top cover by unscrewing the nuts.
When the device is disassembled and access to the heat exchanger is provided, you can start cleaning it:
- remove the heat exchanger;
- put it in a solution with an active substance - a light solution of hydrochloric acid;
- carefully, but gently clean from dirt with a brush or a metal brush;
- rinse well in clean water;
- dry.
After such actions, the heat exchanger and the dismantled parts are installed in place. Before disassembling the gas boiler, it is recommended to study the instructions that came with the device.
Such washing is carried out using a booster. But the device is not cheap at all. Therefore, many craftsmen make a special device on their own. For this, a ten-liter container, a pump and two hoses are used.
In chemical cleaning, it is important to choose the right acid solution so that the substance does not damage the metal parts of the boiler. For severe scale, products based on hydrochloric or sulfuric acid can be used. Lighter contamination is cleaned with citric acid, two hundred grams of which is diluted in five liters of water.
The process of cleaning a gas boiler with chemicals is quite simple:
- solution for washing is diluted in a container;
- the hoses of the factory or homemade booster are connected to the nozzles on the heat exchanger;
- the device is turned on and a chemical liquid moves inside the closed system.
Factory boosters are equipped with a heating mode. This function allows you to increase the temperature of cleaning solutions, thereby improving the quality of cleaning.
Washing the gas boiler heat exchanger with chemicals should last at least two hours. After carrying out the entire procedure, remove the reagent and rinse the device with a neutralizing agent, which is selected depending on the agent used. After a solution with citric acid, you can treat it with soda dissolved in water.
The disadvantage of frequent chemical cleaning is the negative effect of active elements on the metal elements of the boiler. Therefore, this type of flushing is recommended to be done no more than two or three years later.
For chemical removal of scale and contaminants from the heat exchanger, the following means are used:
- Cleaning gel. The composition of such a substance does not include acid, but regardless of this, the gel copes with various types of pollution, salt deposits and scale. After treatment with such a substance, washing with neutralizing solutions is not required. All parts can be cleaned with plain water. The gel is considered a more gentle agent for metal products.
- Adipic acid. To flush a gas boiler, such a reagent must be properly diluted in water, otherwise the substance may damage metal parts. Adipic acid well softens all deposits inside the heater. To clean with such a tool, remove the heat exchanger and allow it to cool. After the cleaning agent, the device must be washed in a neutralizing liquid composition and dried.
- Sulfamic acid. The activating agent is diluted with water and poured into the heat exchanger using a booster. Such a reagent effectively breaks down complex scales and saturated salt deposits. Usually used for flushing running contaminants. Thorough washing after a solution of sulfamic acid is required.
When working with chemicals, safety precautions must be followed. Dismantling of heating devices is carried out only after a complete disconnection from the supply of gas and electricity.
Hydrodynamic cleaning
Such flushing is carried out without dismantling the boiler. The process consists of pumping water into the heating system and pressurizing it. In this case, sometimes an abrasive substance is added to the liquid.
By increasing the movement of water, scale is effectively destroyed, and various contaminants inside the system are well washed off.
With such cleaning, it is important to properly organize the level of pressure, otherwise pipes may burst. Therefore, hydrodynamic flushing is not recommended to be done independently. This process is carried out by specialists who have permission to work with gas equipment.
Distinctive features of cleaning a single-circuit and double-circuit boiler
The type of heater does not affect the frequency of flushing the heat exchanger. Both a single-circuit and a boiler with two circuits need timely cleaning.
A distinctive feature of flushing a boiler with a water heating function is that in addition to cleaning the main heat exchanger, it is necessary to remove scale from the DHW paths.
The method of flushing the hot water supply path in the boiler depends on the type of heat exchanger, of which a boiler with two circuits has two:
- steel secondary;
- combined bithermic.
- connecting the hoses of the cleaning device to the nozzles intended for the outlet of hot liquid, as well as to the inlet of the cold water supply;
- start booster;
- turning on the boiler.
In this case, the temperature regime of heating should be observed within fifty and fifty-five degrees above zero.
If there is a secondary heat exchanger in the double-circuit boiler, then it can be dismantled for cleaning. For this you need:
- remove the front panel;
- unscrew the fasteners from the control unit and move it a little to the side;
- remove the fasteners from the secondary heat exchanger and remove it.
After that, the device can be cleaned by dipping into a solution with an active solution. Well removes scale citric acid. It is diluted in containers with water, a secondary heat exchanger is placed there and boiled over low heat until the deposits are completely dissolved. Be sure to rinse all treated parts with clean water or soda solution after cleaning.
For a single-circuit boiler, only flushing of the main heat exchanger is required. The main thing is to prevent the formation of strong pollution and scale. It is better to carry out a light preventive cleaning than to subsequently wash the heat exchanger with strong metal-destroying substances.
Flushing a gas boiler is a mandatory process that should be carried out in a timely manner. The reliability of the heater and its service life depend on the observance of the frequency of cleaning and its correct implementation. To avoid unnecessary costs, you can eliminate small scale yourself. To do this, you need to choose the necessary cleaning method and study the technique of its implementation.