Common Boiler Problems

Experiencing issues with boilers is never ideal, it can be stressful knowing it may leave your household and family without hot water and heating. To help ease this stress we've included some of the most common boiler problems along with a few suggestions on how to fix them. Alternatively, you can talk to a Gas Safe registered engineer, at Castle Heating Kent, who will be happy to help you with any problems. Simply call on 0800 0016511 01634 790511.

Here are a few common boiler issues you may come across

Hot Water but no heating

Boilers should provide your home with central heating and domestic hot water. If you are getting hot water but no central heating there's a problem.

Thermostats control the temperature of your central heating, as well as the time, it should come on. Therefore, the first check is to ensure that your thermostat is fully functional. If it is working but the heating hasn't come on hot enough or at the right time just double-check the settings.  

You should then check to see if the boiler pressure is too low. boiler pressure is the term that describes the pressure of the hot water that runs through the central heating system. If the boiler pressure is too low, the heating will stop fail to work. This can be fixed by yourself or an engineer if you're unsure.

If the boiler pressure and thermostat aren't the cause there are other causes. These causes will require professional repair and include broken diaphragms, airlocks, or a failure of the motorised valves.

No heat or hot water

A boiler's role is to provide your home with heat and hot water if it isn't then you'll want to get it fixed as soon as possible.

There is no single issue that will lead to your boiler failing but possible issues you can check include:

  • The thermostat not working or it's set lower than room temperature.
  • Low boiler pressure to avoid this make sure that the boiler is set to the manufacturer's instructions (this is typically between 1 and 2 on the pressure gauge).
  • The pilot light going out. Older boilers have a pilot light if this goes out then the boiler won't be able to fire into action.
  • A frozen condensate pipe. This pipe transports waste outside to an external drain so there's more chance of it freezing in winter. In some cases, it can cause the pipe to burst. To fix the problem thaw out the pipe and to avoid this issue in the future add spacially designed insulation called lagging.
  • A lack of fuel. If you have a gas boiler make sure your supplier is still supplying fuel.


If your boiler is leaking it's a problem. The cause will depend on where the water is coming from. Unfortunately, a boiler leak is a major issue and should be repaired by a Gas Safe Engineer.

The most common cause is a broken internal component, this could be a pump seal or pressure valve. If the issue is the pump seal it could be because of high boiler pressure. should the issue be the pump seal this may be an indication that it is worn out and needs replacing.

Other issues could include corrosion or be a result of poor installation. We recommend calling out our Gas Safe engineers to diagnose the problem.

Get in touch

If you're experiencing boiler problems and are located in and around Kent including Snodland, Maidstone, Rochester, West Malling, Gravesend, and Aylesford get in touch. Castle Heating Kent is Gas Safe registered and is happy to help diagnose and repair any boiler issues you may have. Simply call on 0800 0016511 or 01634 790511.