How to fix one cold radiator – Plumbing Tips

Do you have one cold radiator that needs fixing? Would you like to try fixing it yourself? Roger Bisby troubleshoots that problem radiator.

“If you have a radiator that isn’t getting hot there are a few things potentially happening.

“Your central heating might be on and your other radiators are warm but you have one cold radiator.

“If you feel the radiator and you find that there are cold spots but that it’s getting warm at the top then the problem is sludge which is basically the system corroding away which is building up a layer of sludge which is oxide in the bottom of the radiator which means the water isn’t able to find its way through. If the problem isn’t too severe you can inject a little bit of sludge remover or system cleanser into the radiator and let that run round the system for a few weeks and then drain the system. If you can’t do that, the next step is to take the radio down and take it outside to be flushed through with a hose. If that isn’t effective the next option is a power flush.

“Another common problem is air collecting along the top of the radiator which means that the bottom is hot and the top is cold. In that situation you need a radiator key, my preference is a brass one and then you need to find the bleed screw on the end of the radiator and turn it using the key. You only need to turn it a tiny amount until you hear it hissing and see some water come out which means that the air has gobe and the water is in the top. If you find you have to do this regularly it means that you have air coming into the system in which case you need to have the system looked at. If you are having to bleed them every few months it means you might have corrosion which might lead to leaks in your radiators and even your boiler.

“Another common problem is with the pipe leading into the radiator getting hot but no further. Very often radiators have thermostatic radiator valves and sometimes they jam. Once you take the actuator top off you will see a pin at the top of the valve which you can move it up and down and it should start to function.”

Balancing radiators is another common issue and balancing your central heating system will be covered in another video.

About Roger Bisby

Roger Bisby
Roger Bisby is an English television presenter and journalist, known for his expertise in the British building industry.

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