Radiator problem - Plumbing Forum | Plumbers Forums

flame · 24-11-2008

I'm currently decorating what is going to be the nursery in our house and we have a problem with the radiator in that room.

All the other radiators in the house work fine and heat up with no problems, and this is the only one with a problem. It never gets any hotter than lukewarm.

The valve to the right (thermostatic valve??) is red hot to touch when heating is on, yet radiator is not. And the valve on the left (lockshield valve??) is cold always.

Can anyone suggest something that might help me, as I'd rather try and sort this out before I have to pay someone to come out and fix it?

* I've bled all the radiators in the house - no probs there.
* I've tried turning all other radiators off except the problem one - nothing changes.
* I've taken it off the wall and emptied out any water and put it back on, bled it, etc - still no changes.
* I've been up in the loft and checked the water tanks. Both are full and there appears to be no problems there.

Can anyone please suggest anything else to help me?

Thanking you in advance for anything you offer...

plumbingmad · 24-11-2008

sounds like the TRV is playing up...I presume you have tried opening this fully?
It may be jammed shut and need replacing.

flame · 24-11-2008

Thanks for quick reply.

Yep, I've opened it up fully.
Is there any way I can tell if it's shut and damaged?

MarkB · 24-11-2008

Sometimes the pin in the TRV gets stuck. If you can get the head off the valve there should be a pin sticking up in the centre. It's spring loaded and may be stuck shut down. Try pressing on it to see if it moves. It may release, if it doesn't you may need a new valve.

aceone · 24-11-2008

Yes i agree with Mark...carry out his instructions and all should be well

plumberdan · 02-12-2008

Remove the trv head and hopefully the heat will come through - sometimes its just teh pin in the trv head has siezed up and holds the valve pin constantly closed. If this is the case only the trv head will need to be replaced.

dontknowitall · 4 Weeks Ago

I sorted one out a week or so ago ... if the TRV is functioning okay, it's possible it's on at the wrong end - before they came "dual flow" (or whatever they're called) they had to go on the flow end of a radiator. To test the flow end, put your hands on both pipes when the heating is turned on (after it's cold). The end that warms first is the flow and this is where the TRV should be.