Hot pipes, cold valves?? Radiator help for a beginner please!

[Ajbrox]

my bathroom rad is stone cold, all my others are fine. The pipes leading to the valves are nice and hot, I've tried bleeding the air out via the top screw but it's not got any air in there it just dribbles water out...am I over looking something simple here? Could the adjustable heat valve on the other end somehow be jammed shut? Or is there something to be tried on the brass looking one on the opposite side? Pics included. Thanks for any help!

 

[Dan Robinson]

Search the forum for "stuck trv", or "jammed trv".

Post back afterwards.

 

[Terry lambert]

Have you tried shutting other radiators to see if that then pushes heat through to the bathroom rad?

The pin could be stuck on the thermostatic valve, take the head off and pump the pin with the top of the head, if it moves in and out freely then fine, if it is stuck, get some pliers and try to ease the pin out.

 

[dilalio]

Wot they said

 

[Jackrae]

Is it an optical illusion or is the pipe coming out of the wall to the thermostatic valve actually not connected to the valve. If not then as previously stated a stuck pin in the thermostatic valve. Don't pull it too far or it'll pop right out - usually followed by a stream of water!

 

[Dan Robinson]

Its one of those clip over things to make copper look like chrome..... which never works

 

[Ajbrox]

Its one of those clip over things to make copper look like chrome..... which never works

It is...but it's plastic not copper

 

[Ajbrox]

Have you tried shutting other radiators to see if that then pushes heat through to the bathroom rad?

The pin could be stuck on the thermostatic valve, take the head off and pump the pin with the top of the head, if it moves in and out freely then fine, if it is stuck, get some pliers and try to ease the pin out.

I removed the valve as you suggested and the pin seems to ping in and out freely enough. I will try and shut off a few rads to see if that helps. Should I shut off the ones nearest the bad radiator? If this doesn't work could it be a bad valve on the opposite side to the thermostat? Thanks.

 

[jackthom]

Does the TRV pin spring out when released. It shouldn't be loose but should resist being pushed in.

 

[Terry lambert]

Is it an optical illusion or is the pipe coming out of the wall to the thermostatic valve actually not connected to the valve. If not then as previously stated a stuck pin in the thermostatic valve. Don't pull it too far or it'll pop right out !

Anyone reading this, if you pull too hard and the pin pops out, Pop it straight back in

 

[Ajbrox]

Does the TRV pin spring out when released. It shouldn't be loose but should resist being pushed in.

It's not loose it has some resistance.

 

[dilalio]

If the TRV and the Lockshield valves are working as they should be then it would appear to be either a balancing problem or that the radiator is blocked internally with sludge!

The purpose of shutting all other rads in the property off would be to force all flow from the pump to that one, defective radiator. If there is sludge in that radiator, the focussed flow will hopefully be enough to get the sludge dissolved and system water flowing through it again.

On ALL other rads: turn the TRV heads right down to 1 or 0 or *.
On the defective rad: turn the TRV to its highest setting AND use a pair of pliers to fully open the Lockshield valve (anti-clockwise). Turn on the heating. See if that rad gets hot and works as it should. Leave in this state for maybe an hour to get that loop circulating. If it goes well and starts working then start to bring the other rads back online.

If after this the rad goes cold again, look up how to balance radiators.

 

[gasmanstu72]

try tapping the TRV with a hammer (or something) it could be that the pin is free but the valve is still stuck on the seating,

 

[Wongfeifox]

As above, just because the pin moves doesn't mean the valve seating isnt stuck, if tapping it with a hammer doesn't free it up it will need replacing.
To test everything that has been stated.
1: keep the trv head on but turn it down to 0
2: wind the lock shield valve right down shut.
3: remove the rad, now you can also check whether it is full of sludge, the water coming out will reveal all
4: hold a tub/bucket near the trv and turn it up to max, you should get a good flow of water coming out, be careful.
5: if no water comes out replace the valve (this will require you either releasing the pressure if a sealed system, air locking/bunging if it's open vent, or draining if you don't know how to put an air lock on)
6: if you get this far and all is ok at the trv end try the same with the lock shield valve, highly unlikely this has failed, but I replaced one last week because the cust had broken the spindle from the seating.
7: if all is good then you have an issue with the pipe work, being plastic you can expect it at some point in the systems lifetime.