Read us to know the causes and solutions for when radiators stay cold

My radiator is cold and not working, how do I fix it?

While cold radiators could be a result of a more serious problem with your central heating system or boiler, there are a number of smaller faults that should be ruled out first.

 

Get a new boiler quote   

 

The thermostat’s set too low

 

Check that the thermostats in your rooms and on the boiler are set correctly. Your manufacturer's manual will provide details on the correct settings.

 

The timer or programmer isn’t working

 

Check that the timer or programmer is switched on and set correctly. Your manufacturer's manual will provide details on the correct settings.

 

The gas boiler's pilot light’s out

 

If you find that the gas boiler’s pilot light has gone out consult the relighting instructions that can usually be found printed on the back of the boiler’s front panel.

 

There’s a build-up of rust and sludge

 

If you suspect that there’s been a build-up of rust or sludge in your radiators there are two ways to remove it, depending on the type of system you have:

 

  • For open-vent systems

For heating systems that are conventional, un-pressurised and tank fed, you can use a heating system sludge remover.

Available from most DIY stores, simply add the liquid to the feed and expansion tank and, after a few days, empty and refill the system.

 

  • For non-open vent systems

If you don't have an open vent system, you'll need to flush your radiators with a hosepipe. Your manufacturer's manual will provide further information on how to do this correctly.

 

There are air pockets in the system 

 

To remove any air that’s become trapped within your central heating system, bleed your radiators.

 

Get a new boiler quote   

 

Information and other materials on this website are not intended to constitute professional advice and should not be relied upon. Please see our Terms of Use for further details.

Related articles


Bleeding a radiator

How to bleed a radiator

Bleeding a radiator is an easy and cheap fix for combatting cold and patchy radiators. It's something anyone can do in their own home without the need...
Boiler is working but radiators stay cold

What to do if your radiators aren't working

Finding that your radiators aren’t heating up even though your boiler is working as it should, could leave you stumped as well as cold. If your boiler...
Cold patched on a radiator

How to fix cold patches on radiators at the top, middle or bottom

Cold patches appear on radiators when your water supply is unable to properly flow through your central heating system due to air or substances such...