Boilers and their 7 most frequent faults

There are many types and models of heating equipment. Boilers are the most popular heating systems in the world.

Even so, it is essential to know that they require regular maintenance and inspections to ensure their correct, safe, and efficient operation.

Why is proper maintenance of the boilers necessary?

One of the most critical aspects of heating installations and, in this case specifically, of boilers, is their maintenance. Not only the boilers should be checked, but also the heating circuit. Many users think that this is an unnecessary expense until they realize how expensive it is to fix them once they break.

In order to maintain energy efficiency, it is vital to avoid emissions of undesirable gases into the atmosphere. By doing this, we also ensure the safety of our facilities and personnel. It is also worth considering that a poorly maintained boiler, in addition to increasing consumption and costs, does not generate the same amount of heat.

What are the consequences of neglecting boilers?

When boiler maintenance has not been carried out consistently, it can present a series of problems that can have a direct impact on monthly consumption. Moreover, it increases the probability of emitting dangerous gases.

Therefore, the boilers need not only preventive maintenance but a scheduled annual control, which allows us to extend the life of the system. If we avoid maintenance, problems will likely arise in the operation of the boiler, resulting in breakdowns.

The most frequent are:

If the heating system has a sudden blackout, the temperature can rise very fast, or on the contrary, the radiators could be failing to heat up. The fault may be due to a wiring problem or a sensor that blocks the recirculation pump. It is a severe problem that should be fixed as soon as possible.

Another fault that is usually more serious is the obstruction of the smoke outlet. Often, an error appears in any of the indicators that the boiler has and subsequently crashes. It is because carbon monoxide is not evacuated through the outlet duct, and, for safety, the boiler self-locks. In this case, you should contact a boiler repair service.

Sometimes it happens that the flame of the boiler does not ignite, and in this case, it is likely that the fuel suction filters are dirty. The solution is simple, but a technician must still review the heating system just in case.

Pressure drops can be very unpleasant and usually appear over time. It means that the system is not heating properly. This is an issue that you might be able to solve on your own. To get it to work correctly again, fill the circuit with the pressure recommended by the manufacturer of your boiler.

How to do preventive maintenance in boilers?


  • Verify:
    Water level and combustion.
  • Purge:
    Background, scale, and surface:
    Pressure/temperature feed water
    Fuel gas temperature
    Fuel oil temperature and pressure
    Gas pressure
    Atomizing air pressure
    Supply and return water temperatures
    Water consumption replacement
    Vapor pressure


  • Check:

Adequate fuel valve closure
Air and fuel connections
Indicator lights and alarm
Limiting and operating controls
Security controls and connections
Filtration, noise, vibrations, abnormal conditions, etc.


  • Refractory inspections
  • Check the electrical components
  • Clean:

Low water faucet
Oil pump, strainer, and filter
Air cleaner and air/oil separator
Compressor coupling alignment (fan)


  • Inspect the inside surface of the container
  • Clean:

Chimney sweeping of fire pipes

Water chamber inspection

If you follow these steps, you’ll ensure the proper functioning of your boiler. At the same time, you will achieve efficient energy consumption, which is reflected as savings in your power bills and security for your facility’s personnel.