What’s up with my boiler?

Central heating is definitely something we take for granted. We just always look forward to it switching on and warming us up and when something goes wrong, it can catch us by surprise and leave us stranded with no hot water and no way to keep warm. This is also always a problem that happens in the bleak mid-winter! Here we look at some of the most common boiler problems:

There is no heat or hot water

This is often caused by a defective component, a failure of the valve, the water level being too low or a problem with the thermostat. The first place to check is the thermostat and boiler pressure to see if it needs adjusting. If the problem is a damaged diaphragm or airlock, these parts will most likely have to be replaced. If you cannot identify a problem or suspect that something needs to be replaced, call a registered gas engineer. For Bristol Boiler Installation, visit a site like www.greenerhomesgroup.co.uk/boiler-installations.html

Image credit

Odd sounds

If you start to hear sounds other than the usual sounds of humming from your boiler, a common issue is air in the system. Perhaps the water pressure is too low, or your boiler is kettling. Kettling sounds like a kettle about to boil and is caused by the buildup of limescale in the heat exchanger. Dirt may accumulate, affecting the flow of hot water and causing it to boil. A pump failure could also explain the strange noises.

Dropping pressure

A boiler pressure dropping too low can result in your central heating was not working properly. Checking the pressure gauge will give an indication if there is a problem, especially if it is below 1. There may be a leak somewhere causing a pressure drop or the valve needs to be replaced. If you are in doubt of any kind, call an engineer.

Pilot light

This can be caused by a draught or dirt accumulation on the pilot light or a damaged thermocouple.  Check if there is a problem with your gas supply as a whole, but if not, you can try to reignite the pilot light by referring to the manual. If this does not solve the problem, contact an engineer.

Cool spots on radiators

If you find that your radiator does not reach the temperature it should, this could be a build-up of dirt or air in the system causing an uneven distribution of heat. This will involve bleeding your radiators which is an easy enough action. If certain radiators in your home do not warm, they may need balancing. Again, this is an easy task and involves adjusting the valves on each radiator to ensure each receives enough hot water.

Image credit


Seeing your thermostat is inaccurate or randomly switching the heating on and off, it’s probably time to replace it. Make some simple checks to make sure it is turned on and the settings are correct. This could be the case that your house is warmer than you think it feels and the thermostat will not allow your boiler to heat up further away from the set temperature. If you cannot immediately identify the problem, call an engineer.