Boiler repair: the 7 most common causes of boiler failure

You take your shower and you have no more hot water? Does your radiator seem to make strange noises? It’s colder than usual in your home, and touching your radiators you have the impression that even on, they do not heat? It’s clear, it’s almost certain that you have a boiler problem. Many breakdowns can occur when it comes to boilers! What are the 7 most common causes?

1 – The boiler makes strange noises

A professional would tell you: all the components of a boiler can cause various noises. Sometimes the machine bubbles, other times it hums and it can happen that it whistles. Try to spot this sound so you can possibly describe it exactly to a professional. If you can, see where this sound comes from because location plays an important role in analyzing the cause of the failure. Do you hear the noise, for example, at the level of the boiler itself, or rather in the pipes or at the level of the radiators? In principle, there are many possible causes and the solution to remedy the failure is not necessarily the same. Some noises may bother you, but they are not a sign of a fault. Many older boilers have a constant hum that you can safely ignore. However, this buzzing can also indicate a serious heating problem, such as the internal boiler pump being faulty. If you are having this problem and the noise is relatively loud, professional help would be recommended and welcome.

2 – There is air in the heating circuit

This is the classic of boiler failures. If you hear a bubbling or gurgling sound, in most cases you can remedy the situation yourself. This is a sign that air has accumulated in the radiators and throughout the heating circuit. Purge your radiators! Follow these steps:

  • Turn off your heating system’s circulator and wait 30 to 60 minutes for your radiators to cool.
  • Locate the bleeder or the bleed screw (it may look like a brass key), get a bleed key or simple pliers, a container and a rag.
  • Open the bleed valve on each of the radiators one after the other. Let the air out. If the hissing stops and water escapes, close the valve.

Regular purging not only reduces annoying noises, but also saves you energy. As a result, the water can again be better distributed in the radiators, which increases energy efficiency.

3 – The boiler does not start

The worst boiler problem is one that affects the system as a whole. The first of the steps you should take would be to check if there is any problem that you can easily fix. For example, did you accidentally press the emergency switch? Does your boiler work in summer mode instead of winter mode? If you are not in any of these situations, you should call a professional.

4 – The boiler is no longer supplied with fuel

If your boiler is no longer working, it could simply be due to the fuel supply. Because your boiler is not likely to start if the burner receives too little or no fuel. This can happen, for example, when the fill level in the oil tank is particularly low. Because the suspended matter clogs the pipes and valves and this results in burner malfunction. It is for this reason that if you have a boiler, you should always refuel when it is only a quarter full.

5 – The system pump is faulty

The heating pump transports hot water throughout the system. This supplies the heating surfaces with energy and the house with heat. If the pump fails, no water flows and your water heater is broken. You can check that it works, for example, with a screwdriver.

6 – The pressure is too low

This is another typical boiler problem and it can have various causes. A poorly adjusted safety valve can understate the pressure. A faulty expansion tank is also a possible cause. If this problem occurs immediately after purging, add heating water. In the worst case, small or large leaks have formed in the heating circuit over time. A professional repairman can locate these leaks and make them go away. He can solve this problem by looking at the pressure gauge. This is either built into the boiler or attached nearby. If you have a detached house and the display does not indicate at least 1 to 1.5 bar, you must add water to the system. If the pressure drops again and again, this may indicate, for example, a defective expansion tank. In this case, an installer will be the hardest to help you out.

7 – The setting is wrong

The heating does not work if the heating command is incorrect. In summer mode, the heating function is deactivated when the system is well adjusted. If, on the other hand, your radiators remain lukewarm on particularly cold days, an incorrect setting may be the cause.

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