Radiators aren’t warm enough

While your boiler and radiators might be in good working order, from time to time you may find that your heaters aren’t getting fully hot.

In order to maximise their output follow the steps below:

  • Check that the radiator valve is open

  • Ensure that the radiator thermostat valve is set correctly

If your radiator has a thermostat, check that the valve hasn’t been set too low. If you discover that the valve is faulty contact your local heating engineer.

  • Check that the lockshield valve is set correctly

Located at the opposite end of the radiator to the main valve, the lockshield valve controls the flow of hot water into the radiator. In order to allow more hot water to pass you may need to adjust the settings.

  • Check whether the valves are blocked

If your radiator valves are blocked with limescale you may need to flush your system.

If you have an open-vent system (a conventional central heating system which is un-pressurised and tank fed), you can use a heating system sludge remover that can be bought at most DIY stores.

You can flush the system yourself by:

  • Adding the liquid to the feed and expansion tank
  • After a few days you’ll need to empty and refill the system

If you have a non-open vent system you’ll need to flush your radiators with a hosepipe.

If you’re finding cold radiators in different parts of your home you may need to refill the cistern tank or replace the pump.

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.

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