TRV - Thermostatic Radiator Valve pin

Brooksie · Dec 28, 2008

If have a radiator fitted with a Drayton TR4 TRV on the flow side. The radiator is not getting warm at all. The supply pipe work is warm up to the TRV valve body.

When I screw off the adjustment section of the TRV the pin is exposed and it can be pushed down, agains some resistance. Is the wax / liquid in the detached part of the valve or in the body with the pin?

The lockshield valve spindle on the return side of the radiator turns around and around and around and never comes to a stop either fully open or fully closed. Could this be a broken spindle and the valve is closed and hence not allowing any flow?

Have tried WD40 on the pi area incase it's stuck but no improvement

Someone suggested a sharp tap on the TRV valve can release a stuck pin. Does this work?

Any suggestions what is causing the radiator to not warm up?
Thanks
Brooksie

sonray ltd · Dec 28, 2008

trv4 is not wax it is a liquid and its in the top part of the valve.
if you have removed the top of the trv and the pin is moving freely and the rad is still cold i would count the trv out as the fault.

as you say the locksheild valve is just turning.
is it shut or open ? you won't know until you remove it.

you could replace the trv top and close it down so its fully shut then open the bleed valve into a bowl if it keeps on letting water out and not stopping you know the locksheild valve can't be fully shut.

it could also be a airlock in the return pipework.

Andrew Rowe · Jan 5, 2009

Is the lock shield fully open?

How to find out if TRV works?
1.On lock shield side of radiator place a container to catch water.
2.Crack open joint, lock shield to radiator connection.
3.Let water flow out for a few seconds.
Does radiator get hot now?
If yes! TRV ok, lock shield faulty! If no TRV faulty!

Easy ay!😀

Regards Andy