One radiator wont heat up

[Dan Horne]

Hi all

New to the forum.

I turned on the CH today at about 2pm and all rads in the house heated up. I have 5 upstairs all with TRVs and 8 downstairs all without TRVs.

A while after the house was warm i turned the CH off and set it to come back on at 6pm. I checked all the rads about 6.30/7 and all of them were working fine except for one of the TRV ones in a bedroom upstairs.

I have ensured TRV is fully open, as is the valve on the other end (turned anti clockwise). I have even taken the top of TRV off and pin can be pressed up and down. The only thing is both pipes come from the wall to the valves are cold. I dont get it as this rad was working with all of the others earlier. All rads have been bled and no air in any of them.

Just checked and all rads are hot (top to bottom) its just that one which is cold.

Any help would be greatly received.

Thanks

 

[gigz]

Turn the rest off and run this one on its own.

 

[Dan Horne]

Thanks. What do I then do with the rest if that solves the issue with that one? Just turn them all back on?

When turning them off is it just the TRV end or the lockshield end too?

Thanks

 

[gigz]

Just the trv. When (if) the rad starts working, you will probably hear air gurgling. Give it a few minutes then turn the rest back on.

 

[Dan Horne]

Thanks for this. If this works and then I turn all the others on is there a chance the problem can pass to another? If so, then is it likely to be the last one turned on or should I turn them back on in any order?

Finally, the ones with no TRV is it turning clockwise to turn off?

Thanks

 

[gigz]

Don't worry about the problem passing elsewhere (it might never happen). No particular order turning them back on. Yes clockwise to turn off. You may not need to turn them all off, it might start working after a few go off.

 

[Dan Horne]

Ok thanks. So i should turn them off one at a time leaving that one on and then check it. Then as soon as it starts working (if) just turn those ones back on again?

What would have caused it to stop working today after already working earlier on?

 

[gigz]

Yes.
Probably air, possibly bit of crud.

 

[Dan Horne]

Hi

Turns out the black pin/lever inside the plastic TRV head was stuck on off. So i took one off another radiator and put it on that one and it solved the problem.

So i turned on all radiators back on and now two downstairs are stone cold. Neither have TRVs but both on/off valve and lockshield valves are fully open.

Both have been bled but nothing. These were working this morning before turning all off to try and get the one upstairs working which as I say was a faulty TRV.

Any suggestions on these other two?

 

[Dan Horne]

Update - all 5 upstairs (with TRVs work) although need replacement TRV head for one.

6 out of 8 downstairs work.

1 out of 2 is warm and inlet pipe is hot but not heating rad properly (have bled it).

2nd out of the 2 is stone cold and so are both pipes feeding it. Have bled it and both valves are fully open.

These are probably the last two on the rad system before you get back to the boiler.

These were both working yesterday and this morning prior turning all rads off to try and solve issue with one upstairs (which was a faulty TRV head).

Thankfully these are the least important in the house in respect of rooms that need heating but still dont want 2 rads which are on but producing no heat. Can someone suggest what I can try next?

Thanks

 

[gigz]

Balancing. See FAQ.

 

[Dan Horne]

Hi

Thanks i have read on balancing but it confuses me a bit and I dont have one of the thermoreader things.

Is there a simple version without one of those?

 

[gigz]

Not really. Apart from years of experience. Probably the easiest way would be to close the upstairs lockshields, then open them a quarter of a turn. Biggest and furthest rads (downstairs) open lsv's all the way. Try that then its a case of tweaking until you're satisfied. Don't get too hett up about it, as long as they heat the rooms, it'll be ok. And remember heat rises so upstairs only need opening a bit.