Thermostatic radiator valves - why do they always stick?

[Mike Andrews]

I'm having trouble with a thermostatic radiator valve in my central
heating system. Basically, it's stuck closed. It's mounted
horizontally, with pipework feeding into it vertically from below.
It and the whole system is about 2 years old. It's been stuck for
some time. Can anyone help with :
Why are these things so prone to sticking?
How do I take it apart so I can free it up? Seems to be a sealed
unit, but I assume it can't be
Any help and suggestions welcomed.
Thanks
Mike Andrews

[Trevor Yates]

The themo valves I have (which also are prone to sticking) have a knorled
nut under the therm head assembly. If you undo this the top of the head
assembly comes off. You will then see a metal pin (probably standing just
proud of the lower assembly). If you use mole grips you can pull this pin up
and thus unstcik the valve, However, in my experience, putting HMP
lubricant, WD40, etc etc on the pin does not provide a long term solution -
it always sticks again. If this causes you grief I suggest either a higher
quality valve or go back to a manual valve.

Trevor

Mike Andrews wrote in message <3ade12c7...@news.demon.co.uk>...

[.]

They stick because the valve stem gets scaled or full of gook and so
cannot move freeley!. To free up,and depending on the type,remove
thermostat head,liberally spray around pin with wd40 or similar,with
heating on,gently tap the pin,repeat at regular intervals until
hopefully it frees off. Give it regular excercise to prevent future
sticking.

joe

[R P Bullock]

In message <3ade12c7...@news.demon.co.uk>, Mike Andrews
<mi...@andrews-post.demon.co.uk> writes

>I'm having trouble with a thermostatic radiator valve in my central
>heating system. Basically, it's stuck closed.

Mike,
You are not alone. I find that some of my valves (Danfoss) have
always stuck closed following lack of use during the summer months. Now
I just consider the unsticking to be part of the 'switch on' ceremony in
the autumn. I posted the following to another query a few weeks ago:

You didn't mention the make of the TRV, but I have found that the old
style Danfoss TRVs stick for a pastime.

On the chance that it is a Danfoss

. remove the TRV hand wheel by loosening the retaining collar.

. this should expose a metal pin. Hold the pin with pliers (and
some care) and push/pull it in and out. You can pull it right out - in
which case it will drip a bit - just push it back in. There is a
diaphragm (or something similar) inside the valve which the pin works
against and is the open/close mechanism. Keep working the pin and the
diaphragm should free itself - you will feel it when it does (because it
starts to work). If the pump is running you will hear and feel the
water shutting off and, of course, the radiator will get hot!

HTH

Bob

--
R P Bullock

[Martyn]

I believe the general advice is to leave thermostatic valves in the
fully open position when not being used for a long period (i.e. over the
summer). Then when you come to use them you can 'unstick' them by
screwing them closed, as opposed to hoping that the internal spring will
be strong enough to push them open & unstick them.

[ian_c...@my-deja.com]

"Alan R. Winstanley" wrote:
>
> There is no such problem with Honeywell or Drayton TRVs which use a
> liquid filled capsule, much more reliable (and twice as expensive).
> Cheap B&Q TRVs are also the metal pin variety I'm told. I'm about to
> swap everything for Drayton valves.

Hi Alan

There is a metal pin in the TRV4. Brass, approx 3mm diameter. It is
'plunged' in and out of the actual valve by the temperature responsive
head, or can be driven in using the 'maintenance head' which effectively
turns the valve into a manual one.

Maybe you meant a different pin or model, but I didn't want you getting
all disappointed after buying them.

HTH
IanC

[bigjim...@gmail.com]

When I served my time as a heating engineer , we were taught to put a high temp grease on the pins of TRVs ( something like copper slip nowadays ) also when shutting or opening a manual valve to open or shut it fully ten give it a little turn other way to prevent seizure , always works .

[bigjim...@gmail.com]

[paulaw...@tuskerhouse.co.uk]

On Sunday, 18 January 2015 17:31:43 UTC, bigjim...@gmail.com wrote:
> When I served my time as a heating engineer , we were taught to put a high temp grease on the pins of TRVs ( something like copper slip nowadays ) also when shutting or opening a manual valve to open or shut it fully ten give it a little turn other way to prevent seizure , always works .

I had these fitted www.radmiser.co.uk they not only exercise the valve once a week they give total control over temperature and time, they are very accurate and now no more sticky valves. they have helped to reduce my energy bill.

[CB]

On 03/06/2015 08:42, paulaw...@tuskerhouse.co.uk wrote:
> On Sunday, 18 January 2015 17:31:43 UTC, bigjim...@gmail.com wrote:
>> When I served my time as a heating engineer , we were taught to put a high temp grease on the pins of TRVs ( something like copper slip nowadays ) also when shutting or opening a manual valve to open or shut it fully ten give it a little turn other way to prevent seizure , always works .
>

> I had these fitted........ they not only exercise the valve once a week they give total control over temperature and time, they are very accurate and now no more sticky valves. they have helped to reduce my energy bill.
>

You could have gone the whole hog and listed prices/suppliers - I have
failed to find any reference to suppliers or prices via google

The only thing I can find is that the company seems to be only 3 months
old........

--
CB

[Tim Watts]

And the product is not available as far as I can see. Nor do they have
any way of signalling the boiler to come on. Which makes them a bit half
arsed.

I helped a relative install Heatgenius which uses Z-Wave Danfoss TRV
heads - and those also do the weekly exercise of the TRV valve. Unlike
your link they are available now, interface with the boiler and have
full remote control.137.73.123.84

[Andy Burns]

Tim Watts wrote:

> 137.73.123.84

Was that meant to be there?

[Tim Watts]

Paste buffer fluff ;) I was configuring a new linux install and was
playing with the KDE cut'n'paste options.

Of no consequence - glad it was a password :)