BOSS TRV replace or substitute?

[MickMann]

Hope this is in the right forum.
We've a utility room radiator with 10mm pipework; fitted about 6 years ago it has a BOSS TRV which has failed (the sensor plunger just flops around - as if the sensor has leaked) and the radiator is always "on".
I don't consider 6 years a reasonable life so I'm reluctant to buy another BOSS head (or whole valve) only to have to replace it in another 6 years.
My questions are....
1. Are BOSS reliable and I've just been very unlucky? (and I can simply replace the head with another BOSS one!)

2. Does anyone know of a reliable brand whose sensor-head would be directly interchangeable? I know Drayton aren't compatible.

Because alternative 10mm valves seem thin on the ground I was tempted to change to a 15mm valve with a suitable pipe adaptor and use a known "good" brand TRV, BUT, because the 10mm pipes come out of a stud wall about 35mm below the valves (via a 90 degree elbow) and within the wall the 10mm copper couples to plastic pipe - unsoldering the 10mm elbow & resoldering a 15mm one may well damage the concealed plastic/copper coupling.
Using a big-name valve with a 10/15mm fitting is out of the question because the short stub of 10mm pipe above the elbow would need the olive removing and cutting the pipe off below the olive wouldn't leave enough pipe for the adaptor & a new olive.
An unwelcome solution would be to cut a hole in the plasterboard to access the copper/plastic coupling before unsoldering and then make good the wall (wife extremely unhappy with this idea!).
A far easier/cheaper option (but no so practical for comfort) would be to leave as is and simply use the lockshield to limit the flow.

Any suggestions welcome, thanks.....

 

[Ric2013]

No idea about BOSS. Not really a common brand, but you probably have just been unlucky. If you want a more well-known brand, Drayton makes 10mm TRVS, and Pegler Terrier aren't bad either. See Screwfix website.

Usually you can pull or knock the old olive off, if you can't get the nut down far enough to carefully saw through it. If so, that leaves you the option of using a 15mm valve with a reducing set instead of a standard olive, so it does the conversion within the valve body (means you can fit 10mm pipe into a 15mm valve) as well as the preferred option of using a genuine 10mm valve. Or, you can do the bodge of wrapping over the old olive heavily with PTFE tape and hoping it will seal to the new TRV body without having to change the olive, assuming the nuts threads are the same as your old valve.

I would advise an amateur against using reducing sets: there can sometimes be a bit of a black art to getting them to seal and you might not have to hand the materials and experience to get a reducing set to seal properly if it is reluctant.

 

[mickymann]

No idea about BOSS. Not really a common brand, but you probably have just been unlucky. If you want a more well-known brand, Drayton makes 10mm TRVS, and Pegler Terrier aren't bad either. See Screwfix website.

Usually you can pull or knock the old olive off, if you can't get the nut down far enough to carefully saw through it. If so, that leaves you the option of using a 15mm valve with a reducing set instead of a standard olive, so it does the conversion within the valve body (means you can fit 10mm pipe into a 15mm valve) as well as the preferred option of using a genuine 10mm valve. Or, you can do the bodge of wrapping over the old olive heavily with PTFE tape and hoping it will seal to the new TRV body without having to change the olive, assuming the nuts threads are the same as your old valve.

I would advise an amateur against using reducing sets: there can sometimes be a bit of a black art to getting them to seal and you might not have to hand the materials and experience to get a reducing set to seal properly if it is reluctant.

Thanks for that, I expect a 10/15 adaptor would use a bigger fixing nut (the 10mm one is definitely smaller than 15mm ones on the other rad's in the house) and that I'd have to remove the existing olive to pass the pipe thru' the new nut & adaptor. In my (very limited) experience, I've never managed to remove an olive by pulling and access is very limited (it's actually in a very small WC).
I didn't realise that Screwfix website shows more valves than are in the paper catalogue.

 

[Ric2013]

Thanks for that, I expect a 10/15 adaptor would use a bigger fixing nut (the 10mm one is definitely smaller than 15mm ones on the other rad's in the house) and that I'd have to remove the existing olive to pass the pipe thru' the new nut & adaptor. In my (very limited) experience, I've never managed to remove an olive by pulling and access is very limited (it's actually in a very small WC).
I didn't realise that Screwfix website shows more valves than are in the paper catalogue.

Correct. It would use a standard sized nut for 15mm tube.

I hate it when access is difficult...