Weak points of gas boilers for the home: what breaks down most often and how to avoid breakdowns

As long as the gas boiler at home is working properly, no one thinks about it. But as soon as something breaks down, problems arise: cold radiators, no hot water. You have to call a repairman urgently. But many breakdowns can be prevented! Let's take a look at which boiler components most often break down and what to do about it.

Malfunctions of gas boiler parts for the home

The burner is the part of the boiler where the gas burns. Over time, soot, smoke, and dust accumulate on it, causing the flame to burn weakly and go out. The boiler works intermittently.

How to avoid gas boiler burner failure:

• Clean the burner of carbon deposits once a year.
• Monitor the quality of the gas. If you often see a yellow or red flame, this is a reason to check the fuel.
• Install a filter on the gas line, if there is none, and replace it periodically.

The heat exchanger is responsible for transferring heat from the gas flame to the water. If the water is hard, scale forms inside. This impairs circulation, causing the boiler to overheat and possibly fail.

What to do to reduce scale formation in the heat exchanger:

• Use filters to soften the water.
• Flush the heat exchanger once a year with special descaling solutions.
• Do not overheat the boiler – set the optimal temperature, usually 55–65°C.

The circulation pump circulates water through the heating system. If air accumulates in it, debris clogs it, or it runs dry, the parts overheat and the pump fails.

How to avoid circulation pump failure:

• Install a filter in front of the pump.
• Pump the system once a year to remove air.
• Monitor the water level in the heating system.

A three-way valve switches the water flow between the heating and hot water supply. Over time, salt and dirt accumulate in it, causing it to either jam or start leaking.

How to avoid damage to the three-way valve:

• Flush the valve once a year.
• Use water filters.
• Do not leave the boiler without water – a dry valve wears out faster.

The expansion tank compensates for pressure drops in the heating system. If the membrane inside it deteriorates or air escapes, the pressure in the system begins to fluctuate. The boiler may shut down or overheat. The pressure in the expansion tank should be checked at least once a year. If necessary, pump it up to 1–1.5 bar.

Malfunctions in the gas boiler's electronics

Boilers have temperature, pressure, draft, and safety sensors. If the mains voltage fluctuates, the sensors may malfunction or fail completely. How to avoid damage to the gas boiler's electronics:

• Install a voltage stabilizer for the boiler.
• Clean the sensors periodically.
• Monitor the condition of the wiring and connectors.

Gas boilers depend on electricity for the operation of the control system, ignition, and heat transfer fluid circulation. If there are problems with the electrical system, the boiler may stop working. Main malfunctions of gas boiler electronics:

• Voltage surges or overloads can burn out the fuse in the boiler's power supply unit.
• The power plug or cord may wear out.
• The control board may burn out due to power surges, moisture, or manufacturing defects.
• If the pump is connected to the power supply but does not work, there may be problems with the wiring, motor winding, or capacitor.

If there are electrical problems, it is important to diagnose them and, if necessary, call a specialist to avoid serious damage to the equipment. If you regularly inspect the boiler, clean the parts, and adjust the pressure, there is less chance of breakdowns. If repairs are needed but you do not have the experience, it is better to entrust the work to professionals.