Central heating: one radiator stays stone-cold but pipe feeding it is really hot. WTH :( <New thermo

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OcUk GD - can any central-heating nerds help :(

I've just had a new thermostat fitted to the boiler. The controller is a wireless affair fixed to the wall in the living room. It works brilliantly.

I dont think the new thermo has ANYTHING to do with my problem but I thought Id mention it.

When I tested the new thermo all the radiators in the house blasted out heat. Except one in the kitchen.

This radiator stays stone cold - but the pipe leading INTO it is really hot. What should I do?

Thanks for any ideas :o
 
Bleed the radiator?

Shout at it?

Turn it on?

Set it on fire?

Poo in its letter box?

Burn the house down?

Buy a new house?

Live in a caravan?

The game is to work out which of these suggestions might be almost sensible...
 
Ahh sorry I forgot to mention an important point: the dial mounted on the pipe is turned to #6 (max setting). Radiator still stays cold.

Edit: bleeding! Hmm that maybe it. Bummer.... I dont have the special key thingy to turn the bleeders.
 
Ahh sorry I forgot to mention an important point: the dial mounted on the pipe is turned to #6 (max setting). Radiator still stays cold.

Edit: bleeding! Hmm that maybe it. Bummer.... I dont have the special key thingy to turn the bleeders.

Maybe it's an inverse scale with 6 being coldest, much like a fridge.

I find that shivs work quite well.
 
Ahh sorry I forgot to mention an important point: the dial mounted on the pipe is turned to #6 (max setting). Radiator still stays cold.

Edit: bleeding! Hmm that maybe it. Bummer.... I dont have the special key thingy to turn the bleeders.

A flat head screwdriver should do the trick. Best done when the radiators are turned off, you'll probably need to let some more water into the system when you're done. Consult your manual for boiler pressure, yadda, yadda, yadda.
 
A flat head screwdriver should do the trick. Best done when the radiators are turned off, you'll probably need to let some more water into the system when you're done. Consult your manual for boiler pressure, yadda, yadda, yadda.

Thanks , i will try that. So kill the boiler (turn of heating) wait a bit and then do the bleed?
 
Even if the radiator is turned on by it's valve the valve inside could be stuck. Had all sorts of problems with some of mine in my old house, give them a light knocking with a hammer (granted that's all the guy that fixed ours ever did and it worked...but it never actually worked for me)
 
You probably need to adjust the flow going into the rad. Where the pipe is hot going into the rad there is a valve, you may to pull the plastic top off, then turn the valve.
 
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Is the entire radiator cold? If so then it's likely to be a valve problem. If the rad is cold at the top but warm at the bottom then an air lock is most likely and bleeding should fix it.

It's worth bleeding it either way as that's quick and simple. When I do mine I have to leave the heating on so that the water pump creates sufficient pressure.
 
You probably need to adjust the flow going into the rad. Where the pipe is hot going into the rad there is a valve, you may to pull the plastic top off, then turn the valve.

^^^^

Radiators usually have a valve at the other end as well (opposite the thermo valve). This is used to restrict the flow to some radiators... It may be totally shut off?
 
We have the same problem with a fancy "designer" radiator in our bathroom. It's never worked despite doing all the usual tricks, and its getting pressing now so we're just replacing it.
 
Turn the heating OFF before bleeding, don't do what has been suggested and leave it on to produce pressure... doing this will introduce more air to the system not remove it.

If you can't work out how to switch the system off, just turn the power off to it, you need the pump to be off.

Almost certainly a valve is your problem, otherwise the radiator would still warm at the bottom, even with an air lock.
 
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