Is this radiator valve broken?

[smp50]

By comparison to other radiators in the house, I'm guessing it is - but I wanted to check with you guys.

My attention was drawn to this after a leak coming from the top of one of the valves, and then I realised that something else is amiss. This is what I have.

Left valve (OK):

Right valve:

The right valve should look like the left one, is that correct? With a protruding stem that allows the internal-most part of the valve assembly to rise up and down when turned. The brass nut on the top of the right valve turns but then of course just releases a lot of water from the pipe.



The funny thing is that I isolated and removed this radiator myself about eight months ago and so must have tightened down this broken right valve somehow. Perhaps it got damaged during later work in the room.

On other radiators in my house both valves look like the left one above.


If I'm right in thinking that the right valve is damaged here then I'll go ahead and replace it.

Thanks,

 

[mogget]

You can clearly see that the shaft has been broken off. Time for a replacement methinks.

 

[HERTS P&D]

In a word......yes.

Andy

 

[smp50]

Thanks - how exciting! More brand new plumbing experiences.

Every job is fun the first time you do it.

 

[smp50]

Before I buy some parts tonight, I have another question. I've removed the valve and the nuts remain as part of the radiator (on the left) and the pipe (at the bottom). Images of new valves show that they come with both of these nuts themselves, for instance:

The blue-arrowed one (the "radiator adapter"?) I can probably remove as inside it is the hexagonal socket for that purpose. But the red-arrowed one is joined to the end of the pipework in a way I can't quite determine, and I'd rather not have to remove it.

Is it normal to change the radiator adapter but leave the old "pipe adapter" in place (if it's sound and not part of the problem) and just screw it back onto the new valve?

Thanks

 

[Charnwood]

The existing blue nut is 3/4" and the existing red nut is 1/2".
Is the blue nut on the new valve bigger than the red?
If so, you'll probably get away with not removing either the blue or red nuts, just replacing the valve body.

 

[smp50]

The existing blue nut is 3/4" and the existing red nut is 1/2".
Is the blue nut on the new valve bigger than the red?
If so, you'll probably get away with not removing either the blue or red nuts, just replacing the valve body.

I haven't bought a new valve yet - I'll take the old one along for comparison.

The valves I've seen in wickes or screwfix are described 15mm x 1/2". I've updated the image above to show the measured diameters of the thread at each point on my existing valve, so in the case of the blue and red labels it refers to the thread not visible in the picture, underneath the nuts.

 

[rjm2k]

There will be an olive on the pipe between the red nut and the valve body.

Unfortunately, in order to change the body you will need to remove the red nut from it. The nut and olive should be ok to leave on the pipe (it will be a pain to remove the olive anyway) and then connect to the new valve body if the olive is still ok. This is a bit of a problem because without the valve body, the water will come out! There are ways to deal with that depending on the system you have, draining down is probably simplest but you will have to refill and add inhibitor (plus some older systems don't like being drained). A pipe freezing kit may be an option though I have never used one.

There are also cleverer ways of doing it.

Also, assuming this isn't in the same room as the wallstat or a bathroom you could put a TRV on there instead but that will need the radiator tail replacing too (comes with the TRV).

 

[smp50]

There will be an olive on the pipe between the red nut and the valve body.

Unfortunately, in order to change the body you will need to remove the red nut from it. The nut and olive should be ok to leave on the pipe (it will be a pain to remove the olive anyway) and then connect to the new valve body if the olive is still ok. This is a bit of a problem because without the valve body, the water will come out! There are ways to deal with that depending on the system you have, draining down is probably simplest but you will have to refill and add inhibitor (plus some older systems don't like being drained). A pipe freezing kit may be an option though I have never used one.

Yep, I've already drained the system and got the valve off. And I took the opportunity to dig half a bucketful of black sludge out of the header tank...

If I can leave the red nut on the pipe that would be preferable.

Also, assuming this isn't in the same room as the wallstat or a bathroom you could put a TRV on there instead but that will need the radiator tail replacing too (comes with the TRV).

Yea, perhaps I could use a set like this:

http://www.screwfix.com/p/15mm-angled-trv-with-lockshield-chrome-white/31811

I removed the tail just now, from one side of the radiator, so that's OK. For the price that's pretty good, and since the room is intended for a lodger in future perhaps they'll appreciate that sort of valve. Presumably the lowest setting is fully "off" no matter what?

 

[rjm2k]

Plenty of PTFE on the tail threads before screwing in, like 20 or so turns

 

[smp50]

Ok guys, I bought this set: http://www.screwfix.com/p/15mm-angled-trv-with-lockshield-chrome-white/31811

and just put them on now (yes, at midnight). The old pipe-to-valve nut/olive business (red arrow in the prevous pic) was stuck firm on the pipes and luckily it fit the new valves anyway so I left those on, but the tail was different and it connected to the valve in a different way to my old ones. An apparently inferior way, I might suggest, since it required a separate olive whereas the old ones didn't.

Anyway, they're on now (with loads of ptfe tape) and look nice - I'll report back once I've filled up the system again. Thanks for your help.

 

[rjm2k]

I thought that about that type of rad tail but apparently they are actually better than the old style. I guess you can get a better seal with the olive and they allow more flexibility with positioning.

 

[smp50]

I thought that about that type of rad tail but apparently they are actually better than the old style. I guess you can get a better seal with the olive and they allow more flexibility with positioning.

Yea, true. In my case it was hard to get on because I had to pull the pipes around a bit to get past the longer tail, but I suppose it does mean it would connect up in more cases when things aren't quite where they should be. Mine were just positioned perfectly for the old ones.

 

[Charnwood]

I've updated the image above to show the measured diameters of the thread at each point on my existing valve,

Your 3/4" is 1/2" BSP, your 1" is 3/4" BSP.

A bit late I know, but it's never too late to learn.