Gas heat exchanger: do-it-yourself flushing

The owners of gas boilers have repeatedly thought that they would like the unit to work for a long time, to be reliable and not create any serious problems during operation. These dreams can be turned into reality, if one minor condition is observed during operation - it is necessary to conduct periodic inspections and minor scheduled repairs if necessary. One of these planned activities is flushing and cleaning the gas heat exchanger.

This operation will return the unit to its rated efficiency. This item must be cleaned once every 2-3 years.

Why do heat exchangers need periodic cleaning?

In the process, soot settles on this element. Sometimes the soot layer is so thick that the efficiency of the boiler drops almost twice. As a result, the unit does not heat up and the owner has to bring the device to full capacity. Prevention measures can remove this soot. But also scale forms inside the gas heat exchanger. Due to this scale, the passage channel is significantly narrowed, the coolant warms up much more slowly. This negatively affects the efficiency of the heating system and increases the load. In addition, energy costs are increasing.

gas heat exchanger

To avoid equipment problems, it is recommended to clean the heat exchangers of gas boilers every three years. This process is a set of works that you can do yourself without special skills. The whole complex of events will take from one and a half to four hours of time.

How to clean the heat exchangers of gas boilers

It is worth noting that this element is a system of pipes, through the internal channels of which the coolant moves. Often, water is used as a coolant, and it is rarely of high quality. The walls of the heat exchanger quickly accumulate salts of various metals, which eventually turn into scale. In addition to the fact that scale is a barrier to the passage of water, it can cause a sharp decrease in the temperature of the coolant.

Among all the existing methods for cleaning this part, one can distinguish mechanical cleaning, chemical methods, as well as washing with water. The latter is fed under high pressure.

heat exchangers for gas boilers

Consider washing the heat exchangers of gas boilers with your own hands, which means that the third option will have to be discarded. For its implementation, you will need a special powerful compressor. It is with high pressure that dense deposits of metal salts can be broken and removed. The other two methods are fine. Everything for them can be found at home or purchased in appropriate stores.

Mechanical cleaning

Choosing this option, it is worth remembering that the element itself in the boiler body takes up a lot of space. It is located in most cases above the combustion chamber. Getting to him is not easy. To gain access to the gas heat exchanger, you need to dismantle the outer parts of the housing. To do this, disconnect the gas hoses and electrical cords, if any. Next, the element itself is disconnected from the pipes. Finally, at the last stage, the mounts are removed.

how to rinse the gas heat exchanger

After that, the part can be removed from the housing and started to clean it. Immediately after dismantling, you can see that the internal cavities of the device are literally clogged with various deposits. Often these are metal salts (sodium and calcium), as well as elements of the so-called ferric iron. They are cleaned with a metal tool - scrapers, pins will do. You need to work very carefully so as not to break the inner walls.

cleaning gas boiler heat exchangers

The device itself can be soaked in a bathtub or basin. A solution of hydrochloric or sulfuric acid is added to the water. When deposits under the action of acids soften, they can be removed mechanically. Experts recommend rinsing the heat exchanger inside with water pressure at the end of the procedure. A lot of dirt will come out of the outlet. It is necessary to wait until clean water flows out of the heat exchanger. Such flushing can be supplemented with light tapping on the body.

Chemical flushing

This procedure is quite complicated, but doable at home. To do this, you will need special equipment called a booster. Before conducting, you need to know the nuances of the procedure. They are, despite the simplicity of the process.

do-it-yourself flushing of gas boiler heat exchangers

The process is simplified, but this simplification lies in the complete absence of any need for dismantling the heat exchanger. Also, you do not need to disassemble the boiler. To implement chemical flushing, it is enough to disconnect the nozzles from the heat exchanger. A hose is connected to one, which will pump the flushing fluid. A hose is also connected to the second. Liquid will come out of it. Inside the system of heat exchanger and booster flushing composition will move in a closed circuit. You also need to know how to flush the heat exchanger of a gas boiler. We will consider possible means that can be made independently or purchased on the market or in the store.

What is a booster

It is a special tank that can withstand the aggressive effects of chemicals. The device also consists of a pump and a heating element. This heater is not available on all models, but experts recommend choosing them for greater efficiency. This will allow you to heat the chemical reagent, which in hot form will act much more efficiently.

Flushing agents

There are many products on the modern chemistry market that are suitable for cleaning and flushing boilers. The choice must be approached carefully. It is made on the basis of two factors - this is the level of pollution, as well as how the reagent will act on the metal of which the heat exchanger is made.

DIY gas heat exchanger

You can rinse the gas heat exchanger with your own hands with citric acid. It copes quite effectively with the removal of minor deposits and scale. Sulfamic acid as well as adipic acid are also suitable. They are practical when flushing is regular and the pollution is negligible. Hydrochloric acid is also designed to remove scale - it removes even complex thick layers of scale. However, here you need to consider the materials of which the heat exchanger is made. Still on the modern market there are special gels that need to be dissolved in water. They, unlike acids, are not as aggressive, but their effectiveness is at a high level, as reviews say.

Experts recommend using saline to flush heat exchangers for gas boilers. It is effective, but you need to be very careful with it. It will cope well with scale and deposits, but in itself is quite aggressive. In addition to these tools, such branded compounds as Sanaks, Sillit, Dketeks and others are suitable for gas heat exchangers.

Features of cleaning plate heat exchangers

These products also disconnect and clean the external as well as its internal surfaces. It will be better and faster if you start cleaning from the outside. First of all, the device must be filled with warm water with the addition of descaling and rust. Then, after some time, the liquid is washed off with clean water. It’s best to do this outdoors with a pressure washer.

clean the gas heat exchanger
After the outer surface is thoroughly cleaned, the internal parts of this element are washed. This operation differs from the usual one in that there is a thick layer of scale on the surface of the walls, which is larger than in conventional heat exchangers. Therefore, for this work, you need to make every effort. It is important to clear the scale completely for better heat transfer.


Cleaning the heat exchanger of a gas boiler is only half the battle. Be sure to clean the soot from the boiler itself and the chimney. Only after this can we say that a complete prevention was carried out. This operation will significantly extend the life of the heating system.


All Articles