1 cold radiator

[red0113]

One downstairs radiator has suddenly stopped heating up. All others are working ok. Any ideas

 

[AnonymousImport]

It could be that the thermostat on your radiator is permanently closed. It may appear to work ok turning the top to adjust the temperature but (as in my case) the valve inside isn't operating (opening and closing to let more/less water through). I took mine off the radiator after draining the system and freed it so the plunger that the thermostat preeses down on to worked again.

 

[AnonymousImport]

Thanks for your reply. I dont have a thermostat on the radiator so thats not the problem. I took of the radiator and flushed it out, lots of black water but no sign of any sludge. When I reconected it, it filled with water but still did not heat up.I turned of all other radiators, just left the faulty one on. Once again it did not get hot ???

 

[AnonymousImport]

Sounds like airlock in pipework somewhere, or blockage. How old is the system, has it been treated with corrosion inhibitors?Obviously both rad valves need to be open - did anybody interfere with the lockshield valve?

You can try flushing the pipework using mains water pressure. You would need to remove the radiator, and connect a hose tail to the rad valve somehow - maybe a washing machine valve would do the job. Connect the other end to a tap supplied directly from the mains - maybe an outside tap or similar. If its an open vented system, you need to cap off the feed and expansion tank - don't forget to remove the cap when you are finished or you will do a horrible amount of damage to you heating system and boiler when you fire it up. You need somewhere for the flushing water to come out - maybe you can remove the safety valve and put another hose on there. Lead it to a good drain, or outside if you can.

Flush out both sides of the offending radiator pipework, remove the hose and bits and pieces, refit the rad, fill the system and test. Hopefully you're now in business. You will want to using a flushing agent in the system for a while to clean it out, follow the manufactureres instructions, drain and refill with corrosion inhibitor. Fernox make good ones, but there are plenty of others.

 

[AnonymousImport]

I have the exact same problem! There are only five rads in my house and the lounge rad is stone cold. The others are red hot!
I've tried bleeding it and have topped up the expansion tank etc but still no joy.
Its frustrating as hell!

 

[AnonymousImport]

Found a drain screw on the boiler so drained the whole system again. Problem is the boiler is on ground level but I have pipes running beneath the floor. When I drained the boiler the pipes beneath the floor would not have drained and could be full of sludge. Reconnected but problem remained. Last night was very cold (frost) so left the boiler on all night. Guess what ! when I came down from bed the problem radiater was hot. Dont know what caused the problem or how it was solved but wish to thank you for your help. I will get some cleaning fluid to put in the system.
Thanks again.
Peter. UK

 

[AnonymousImport]

That bloody radiator has gone off again.Have put some cleaning fluid into the system, will see if that works. I have fitted a new valve onto my system which has a drain tap, I can connect a hose to this and drain the system very fast.
Peter

 

[AnonymousImport]

Pulled up the floorboards next to the offending radiator and found what at first looked like a pump connected to the pipe next to the radiator, had electric wires leading to it. Took off the cover and exposed a type of valve with strong springs inside, pushed part of the valve attached to the spring and instantly the radiator became hot. The spring pulled it closed again, I wedged it open and radiator remains hot, I have fitted a TRV to controll heat. A label on this contraption reads EZV -214. 2 port zone valve. Can anyone enlighten me, have I done wrong?
Thanks
Peter.

 

[AnonymousImport]

The 2 port zone valve was probably fitted previously to control the temperature in the room. It's basically a motorised valve - ie it opens to allow water flow when it is powered up with 240 V, and closes when you remove the 240V. It would have been switched on/off by a room thermostat on the wall somewhere. It might even still be live - so be vareful with it. If you have fitted a TRV you can probably do away with it altogether next time you drain down.

Of course, it may have been working properly all along, just had the wall thermostat turned down too far ???

 

[AnonymousImport]

Thanks for your help.
Peter

 

[AnonymousImport]

I've just had the "1 cold radiator" problem.
I took it off and flushed it out (twice) but with no luck.
Then I found that one of the pipes approaching the radiator was warm (about 3 feet away from the rad.)
I decided that this must mean a blockage in the 'supply' to the rad.
Took the rad off again. Connected a short length of pipe to the valve to see if water would run freely into a bowl.
Some water ran out slowly,then with a big splutter,'muddy'water spurted out (much of it missing the bowl !)and then clear water followed.
There was a large amount of copper coloured sediment in this water so I think that the supply was just blocked.
(The system contains plenty of Fernox).
I put it all back together again (an hour ago) and the radiator is now HOT.
Hope this works for someone else.

 

[AnonymousImport]

A second radiater went off today, turned out to be same problem, a 2 port zone valve that should turn on and of with the thermo control on the wall switch. Electric power is still there but its not working.I wedged it open.I emailed the manufacturer to see if my actions would cause a danger and was told it was safe. Think I must have some more of these valves under the floor, must be an old system. Thanks for your help..Peter

 

[AnonymousImport]

You can usually buy replacement motors for these valves - they burn out eventually. Ask at a plumbers merchants.

 

[pullen]

I had the same problem 1 cold radiator in my lounge. It was a single panel single fin so while I took it off to have a look at it I replaced it with a double panel double fin.
It didn't make a blind bit of difference. However I found that if I turned the pump speed up by 1 it did get hot - not as hot as the other radiators. Is this ok to do this? or will it put to much strain on the system?

 

[jedi117]

i had the same problem and it is frustrating!!

i drained the system ealier on today. after that i refill the system but now one of the radiator downstair is not working!! water coming staright out as i tried to bleed it.

anyone can help please!?