There are a few factors that can cause the radiators in your home to become cold in certain areas.

Follow the tips below to diagnose and fix the problem:

The top of the radiator is cold

Usually attributed to trapped air within the system, to release it you’ll need to bleed the radiator.

The middle of the radiator is cold

Potentially caused by a build-up of rust and sludge obstructing the bottom part of the radiator, to fix cold patches in the middle you’ll need to clean your radiator thoroughly.

The bottom of the radiator is cold

Mainly triggered by a build-up of scale, rust or sludge, which obstructs the flow of water, you’ll need to have your radiator flushed in order to remove the debris.

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.