How to Open That Lockshield Valve to Cure Cold Radiator Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[mth]

Hi all,

we had last year a plumber in that replaced all of our radiator valves. Now that it is winter time, I started the heating and figured out that one radiator stays cold. Bleeding the radiators and checking the pressure didn't do the trick, so the last thing I can think of is that the lockshield valve is not open.
Unfortunately, the type he installed is different to the one we had (I could just use a bleed-key to open it):
https://drive.google.com/open?id=0B5hJCFfDddTSZU5LVU9VbktJZ3c

I guess the topmost bit (the pin) needs to be opened, but it doesn't move even when using a plier. As I do not know this type of valve (why is it even threaded?), would someone please confirm if the pin should (easily) move?

[oldhenry]

Hello
That looks like a normal lock shield valve ,minus its plastic cap. The threads are for a screw to hold the cap on.
I use a 6 mm spanner to open the valve, or a small adjustable wrench. If it is tight squirt a bit of WD 40 down the valve and wait a bit. Frees off stubborn TRVs in the past for me.

[mth]

Hi oldhenry,

thanks for your reply. The reason why I am confused is that I am used to this type of lockshield valve:

There you can see that the spindle looks different than mine. Just to be very clear before I apply for to anything: I have to turn the thin bit that has the thread embedded?

Cheers,
Maurice