Radiator valve - is this the o ring or something else?

[gk_adam]

Hi, first post here been a very helpful forum as I do the bare minimum DIY.

I was trying to balance my radiators following an online guide (https://www.bestheating.com/info/a-best-heating-guide-how-to-balance-radiators/) and messed up one of my bathroom radiators.

This radiator has what I thought was the lock shield valve facing down (left one in pic).

While trying to open it, I somehow damaged it and water started leaking. I noticed this black piece fell out as water continued leaking

As I couldnt stop the leak no matter what, I closed off the TRV on this one and let the rad empty out. Consequently my boiler now has shut down with low pressure warning unsurprisingly.

I had a couple of questions:
-Am I correct that this is the lock shield valve? I was surprised it came off fully whereas the other kind had a hard stop (white radiators with golden valve needing a wrench) so now I am unsure
-looking for the right replacement to buy to fix this myself. Is this the o ring, or is something else? It is 20mm dia but does not feel fully round like the few o rings I have seen elsewhere..

 

[kidgreen61]

That looks like it has a internal screw for which you will need an Allen key to adjust.

You will need to unscrew the whole thing to repair it, using a new O ring, or maybe PTFE tape,

 

[foxhole]

Was that installed by a plumber?

 

[gk_adam]

That looks like it has a internal screw for which you will need an Allen key to adjust.

You will need to unscrew the whole thing to repair it, using a new O ring, or maybe PTFE tape,

Yes I did use an Allen key to adjust, just accidentally overdid it. I'll go look for an o ring at the local store today.

In order of steps then to fix it all back up, am I right in thinking
1) unscrew the valve and fit it back on with new o ring/tape
2) repressurise the system opening the boilers filling loop
3) bleeding any air from this rad. Do I need to do this for all other rads too?
4) turn heat back on

 

[gk_adam]

Was that installed by a plumber?

Yes

 

[terryplumb]

Yes I did use an Allen key to adjust, just accidentally overdid it. I'll go look for an o ring at the local store today.

In order of steps then to fix it all back up, am I right in thinking
1) unscrew the valve and fit it back on with new o ring/tape
2) repressurise the system opening the boilers filling loop
3) bleeding any air from this rad. Do I need to do this for all other rads too?
4) turn heat back on

You pretty much have the above correct. You may need to bleed air from other rads, it will do no harm to check all of them.

 

[gk_adam]

That looks like it has a internal screw for which you will need an Allen key to adjust.

You will need to unscrew the whole thing to repair it, using a new O ring, or maybe PTFE tape,

So I managed to fix it up with tape, put it back in and it's been working fine for 24hrs now. Other thing I realised is I hadn't mentioned this was the towel rod in the bathroom, and not a radiator per se.

It got me thinking though, it may not be a lock shield valve really? I was able to unscrew it out fully using a Allen key. With trv fully open, the towel rod got fully warm despite this other valve being screwed back fully tight. So, I think it's not a lock shield valve? And if it's not that, what is it and did I do it right in screwing it back in fully or is this going to set it up for some damage elsewhere in the system?

For reference I took a photo when I put on the tape

 

[terryplumb]

If you grip the hexagonal part with a spanner to stop the whole valve from moving,can you use the Allen key ( turning it left to right) to close the valve ?

 

[opps]

Earlier this year, I had to remove some of my customer's rads to decorate.

They were similar to the following

Chatsworth Traditional Chrome & Black Thermostatic Radiator Valve - Energy Saving | Victorian Plumbing.co.uk

SHOP the Chatsworth Traditional Chrome & Black Thermostatic Radiator Valve - Energy Saving at Victorian Plumbing UK

www.victorianplumbing.co.uk

I used an Allen key to close the lockshield, the water still pee'd out (pressurised system). I phoned the original plumber. He explained that my customer had supplied the valves and they they could not be fully closed. I had to do a partial drain down and cap the valves. I am used to TRVs that let a little water weap out, but it is the first time that I have experience a new lock shield do that.

 

[gk_adam]

If you grip the hexagonal part with a spanner to stop the whole valve from moving,can you use the Allen key ( turning it left to right) to close the valve ?

Yes I can!

Now I think I understand how it works, and possibly what I did - this is indeed a lock shield valve, and when opening it a couple days back, I did open it all the way but then kept unscrewing with force and ended up breaking the outer casing holding it in place. Correct?

PS: following your method, I now closed the valve all the way and then opened it up one turn to allow water circulation (one turn because originally when I was checking heat flow order, this was the 3rd/4th of the 8 in the flat). Any ideas if I should do differently, please let me know

 

[Madrab]

Yes - the centre HEX section sits inside a threaded outer carrier section that also has an outer thread as in your pic. I think you have undone (opened) the centre hex section which is the lockshield inner valve. That usually gets to the point where it locks and wont unscrew any more. If you kept going after that point the outer section would start to unscrew out of the valve body itself and you end up with the whole valve and carrier out of the body, as in your pic.

 

[terryplumb]

If all radiators are heating fully and at a similar rate,then all is ok.

 

[gk_adam]

Thank you! It maybe small but really like I've grown as a DIYer today