Replacing TRVs but Unsure of Current Setup (10mm pipe but 15mm TRVs?)

[terryplumb]

Hexagonal wrench ( Allen key) to remove from the rad.
The lockshield will have the nut and 10 mm olive left on the pipe after valve is removed.
The TRV will have the male threaded " nut" on the pipe and possibly a 10 mm olive ,but I suspect it will be a mechanical reducer.

 

[Savo]

Thanks Terry,

I have seen a few TRVs that are 10mm so those would work - I would still need to add a coupler on though as cutting the old one off will lower the TRV so I will need to add a bit of length back onto the pipe to get it back to the same height as the rad.

If I was to use a 15mm TRV, would one of these push fit copper fittings do the trick to convert 10mm to 15mm? Just thinking it might look neater than the compression fitting (but not sure if they are reliable as I obviously don't want any leaks!).

https://www.screwfix.com/p/tectite-sprint-copper-push-fit-fitting-reducer-f-10mm-x-m-15mm/2262g

 

[terryplumb]

I would only use a soldered fitting ,much neater and cheaper and the most reliable.

 

[Savo]

Yeah, that's what I thought - just a bit nervous about soldering a fitting as I've not done one before (and obviously would then need to buy a blowtorch etc.).

Thanks again.

 

[wizbongre]

The Danfoss RAS-D range of TRV's are 15mm but come with compressible inserts for 10mm pipes. If you use 15mm pipe you use a straight olive, if you use 10mm you use the compressible insert instead. Dead easy, you only need to treat them as compression joints - I've fitted about 15 with no problems whatsoever. There is a breif moment of panic as the 10mm insert first compresses and the joint goes loose, then it tightens up again like a normal olive.
They are good TRV's too.

 

[rodisi]

Hello DIYNotters,
Sorry for reviving such an old thread but it is perfect for my purposes. My first post hee so please be gentle with me. I decided I was going to change all TRVs and lockshields in my house until I found that they are all the same as the original posting by Savo. The only good thing is that my pipes are 15mm so no reducing. I am hoping somebody will tell me that I can take the present TRV off, remove the olive and nut and replace it with the modern TRV with no problem. Am I dreaming?

 

[terryplumb]

You should start your own thread and show us some pics.