17 Mar 2022
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United Kingdom
Hi. I turned off trv radiator valve (or so i thought ) and lockshield in order to take radiator off the wall, but i gave up as i couldn't undo the lockshield screw - grr - it's totally stuck even with wd40 to help! So i then re-pressurised my combi boiler assuming water had been closed off but it spurted out of trv so i had to connect it back to the pipe again.
It's on the frost setting but there's more marks after that but there are 2 grey pins stopping it - what are they and can i remove them?
If it's any help the radiator is the bathroom, of a fairly cold house!
I've never done this type of diy before so apologies if it's a daft question!
It needs to be off the wall for quite as while as rendering/plastering/painting needs to be done. Then i'm going to have an upright towel rail instead - will this matter? Will it need capping off (whatever that means)?


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The pins usually limit the range of settings, that the TRV can be adjusted to. If they are removed, you get the full range of adjustment, including frost and completely off. A decorators cap, simply allows the TRV head to be removed and the TRV valve pin to be tightly closed.
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Thank you all for your help, it is very much appreciated! I will do as suggested later. Fingers crossed
Thank you all for you great help! FINALLY i have unscrewd the union nut and put a 5p inside the trv - works perfectly as no water is leaking now! Thank you again, all your advice is very much appreciated!
Sorry - me again! Well, trv still leaks a tiny bit from the 1/2" cap but earlier it had a big-ish plurge and drained my boiler.
I read on one forum, unlike most i've read that say turn trv to off position, people were saying turn it to the highest position - due to temp change, would this work? If so can i do it now that the radiator has been taken off? Would it be advisable? Also any ideas as to what other term decorator's cap maybe as it seems places i've been into have never heard of it and online, unless i'm being a right plonker, i can't find one for a Westherm Four! Suggestions very welcome! Thanks
I read on one forum, unlike most i've read that say turn trv to off position, people were saying turn it to the highest position - due to temp change, would this work?

Highest number = valve wide open so no! The TRV head pushes a pin down/in, which stops the flow of water. A decorators cap takes the place of the TRV head, fitted in place of the head - they are less likely for someone to idly come along and turn a TRV head to on. The blank nut linked to in the above post will be even better, it fits in place of the radiator, to the TRV, so even if the TRV leaks a little it will stop the leak. To replace a radiator completely - you may as well get two of them.
Thank you so much for your responses, very helpful. All fixed now. Thanks again

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