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Davey Davey is offline
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Default Sticking radiator thermostat

On Sun, 29 May 2011 12:00:31 +0100
Davey wrote:

On Sun, 29 May 2011 11:48:09 +0100
"Ret." wrote:

Davey wrote:
On Sun, 29 May 2011 08:51:49 +0000 (UTC)
Dean Heighington wrote:

Moonraker wrote:
I have a valve sticking on one of my radiators. It comes on when
called but does not go off (at least we are warm :-) ) I have
swapped the actual heat sensor part with another radiator to no
effect. Is there anyway to free the valve, as I don't want to
have to drain the whole system to replace it, which seems the
only other option.

I usually unscrew the head, turn it upside down and use it to
work the pin slightly, till it frees up... THEN, I do get my
tools if it still sticks and a can of WD40/PlusGas/silicone
grease/whatever and lubricate it. It may be sticking cos it's
leaking slightly.


I have just moved into a house fitted with these, Honeywell made.
They all seem to work more like a setting valve rather than as a
thermostat. Do I not need to drain any water, just undo the head
somehow, and then find a pin under there? I haven't tried anything
yet, other things need more attention!


No, you don't need to drain anything to get at the operating pin -
although if the valves are completely knackered you will have to
drain the system down to replace them of course.

There are various ways of removing TRV heads - with some you might
need a hex key - with others you simply rotate the head to the
'hottest' setting and slide a collar back to release it.


Thanks for the info. These might just move higher up the list now.
I'll try the easiest to get at first, of course.
Thanks.


I easily removed a head, and the pin appears to be free, it is
easily moved up and down, with resultant changes in waterflow. But
looking at the Honeywell website, all integral heads seem to be intended
to be mounted horizontally, whereas mine are all vertical. Could this be
the problem? That they are not seeing room air temperature, but are
affected by the heat in the pipe underneath them? If this is the case,
then a one-time drain-down and overall TRV re-orientation may be in
order before winter.
Comments welcome (useful ones, that is).
--
Davey.