Cold radiator - do I need a plumber?If you are a DIY person these cold radiator symptoms mentioned below might help you to diagnose the problem in your central heating system and maybe to fix cold radiator problem without calling a plumber.
One radiator stays cold – possible reasons:
First check if both valves on the sides of the radiator are fully open. If the valves are fully open, but the radiator is still cold then the valves may be blocked by limescale. In case the valves are blocked, the radiator may need to be flushed out and / or radiator valves changed. Do you have a thermostatic valve? If so the pin in the valve could be stuck and radiator stays cold because there is no flow.
All central heating radiators are cold.
If your central heating is on and your radiators are still cold then your heating system could be full of sludge, stopping the circulation of hot water.
On open vented central heating system you should be able to solve your cold radiator problems just by cleaning your system. Cleaning heating system can be a big job, so you may need to get a professional plumber.
Top part of radiator is cold.
If central heating radiator is hot at the bottom and cool or cold at the top then it's most likely that air is trapped in the radiator. Bleed your radiator and the problem should be solved.
Bottom of radiator cold
This problem tends to be caused by sludge in radiator and the rest of central heating system. Power flush are recommended to remove sludge from radiators and central heating system pipes.
Cold radiators downstairs
If your radiators downstairs are not heating up then there's a very likely that your pump is broken or it is failing. Only one cold radiator downstairs - system balancing might be needed.