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Combination or combi boilers are the most popular choice among homeowners. With its compact and neat appearance and components hidden within the boiler, it can be rather aesthetic. But despite its looks and the added convenience, there are some minor downsides to consider.

To familiarise you with the most common combi boiler issues, we have put together a list of 8 problems that you’re likely to face.

1. Water Leaks

The most common problem with combi boiler installation has to be water leaks and drips. Because you can’t pin down one specific cause for this issue, a DIY repair is usually out of the question. It is something that only an accredited expert should look into.

2. Loss of Pressure

The main reason behind the loss of pressure is water leaks discussed above. But, it’s quite possible that the problem exists due to a faulty vessel that needs to be replaced. So do get that checked preferably from an expert.

3. No Hot Water

The whole point of installing a combi boiler is to heat your home and provide hot water while catering to your daily needs. If your boiler stops performing its primary function you can look for the following issues:

  • Damaged airlock
  • Damaged diaphragm
  • Defective thermostat
  • Defective motorised valves

Replacing the defective or damaged components should fix the issue with your combi boiler. Although you shouldn’t attempt to fix these on your own; calling a heating engineer is recommended.

4. Kettling

If you receive hard water in your home, your boiler will develop a buildup of limescale. This is known as kettling. Limescale clogs the heat exchanger in the boiler and if it this grows too big, steam bubbles with rumbling sounds will emanate from your boiler.

5. Noise and Vibration

Primary cause for noise and vibrations in combi boilers is due to kettling mentioned above. However, low water pressure in the system could be another reason behind the noise. If the noise persists or other types of noises starts emanating from your boiler, it is best to get it inspected by a heating specialist.

6. Absence of Pilot Light

There could be several reasons for this out of which the most common are:

  • The flame being blown out by a draught
  • A damaged thermocouple that needs to be replaced
  • The pilot light has limescale buildup and needs to be cleaned

7. Error in Thermostat

Older units commonly have this issue. When the system is nearing the end of its lifespan, the thermostats often reflect various problems. You need to pay attention to the following:

  • Temperature being misread
  • The system’s switching itself on and off voluntarily

It is recommended that you replace your system with a new one for better efficiency and to avoid unnecessary repair costs. Investing in a new boiler will be justified by way of reduction in your energy bills.

8. Condensate Pipe Freezing

This combi boiler issue is most common with new models as the older units do not have any condensate pipes installed. Modern boilers use condensate pipes to eliminate wastewater. When the temperatures get cold, the water inside the tube freezes and develops blockages. Since replacing these pipes would prove to be costly, it is best to call in a heating engineer at Hunsbury Heating to get rid of the icy blocks by safely melting it.

And with that, we wrap up our list of the most common combi boiler issues. 

Most of these problems need professional attention so it is best to avoid attempting a DIY. You might end up aggravating a small issue while also burning a hole in your pocket.

So give us a call and we’ll send over our certified heating engineer to fix your boiler.