Standard boiler problems and their causes

Historical data indicate that 1 in 3 boilers will break down within their first 6 years of operation. Though disturbing this is a true fact. A boiler can break down anytime due to a variety of reasons. We have analyzed and summarized a list of possible common boiler problems and their causes. This will help you understand different problems and reduce the probability of a complete breakdown.

Rapid Cycling

You might have noticed that the burner turns on and off frequently. This is a clear sign of trouble which needs to be corrected. Rapid cycling can occur due to any one or a combination of causes listed below.

  • The thermostat is installed without proper insulation. This leads to external heat affecting the reading. This can be corrected by having a good layer of insulation.
  • Improper adjustment of heat anticipator in the thermostat.
  • The inaccurate limit setting in the boiler.

Loss of water

Leakage in the boiler piping is the common cause of frequent loss of water. You will end up adding makeup water frequently. You need to hire a proper engineer and fix the leakage as soon as possible.


Noise in the boiler

You might hear a popping or percolating noises in your boiler. This could be due to the minerals deposited in the boiler over time. Minerals can be deposited either due to the frequent use of make-up water or due to invalid pH. These deposits should be cleared and care has to be taken to ensure this is not repeated.

Black color water

Leaks in your boiler pipe will result in oxygen corrosion. This is one of the primary reasons why water turns black.

Presence of metal flakes

The boiler flueway might contain metal flakes. This can occur if the air supply is polluted or gas combustion resulted in condensation. In either case, this has to be avoided and necessary measures have to be taken.


Radiator problems

In some cases, the radiator in your boiler will not heat or there will be excessive noise. This could be due to the presence of air in the module. Other possible causes include low pressure in the system or the high limit has been set too low.

Problems in tankless boilers

One of the most frequently reported problems with respect tankless heaters is that the hot water suddenly turns cold or it is always lukewarm. This can happen due to a variety of reasons listed below.

  • Over a period of time, minerals get accumulated and it insulates the internal waterways of your boiler.
  • Stop-leak compound may be added to the boiler water which will lead to the insulation of outer coil.
  • Invalid mixing settings could be one of the reasons. This is a human error which can be rectified with trial and error.
  • The water flow is too fast and too high for the boiler to heat it in the given instance.
  • Wrong settings made in the tankless heating control. This is again a human error which can be corrected with the help of the boiler manual.

The primary objective of this article is to educate our users to identify and correct boiler problems early and avoid the expensive repairs cost. We have listed only the most common problems, with a full list of problems and their causes click here.