Replacement TRV for 8mm microbore

[pistonheadforum]

Hello,

I have the following and need to replace the TRV



What would I be looking for? 15mm TVR with an 8mm compression internal reducer kit?

Thanks in advance

[mr momo]

If it's just the thermostat*, then there's a direct Danfoss replacement :



Have done this exact change and it works.

• Does that answer your question ?

Edited by mr momo on Tuesday 29th December 20:34

[pistonheadforum]

Hi,

Thanks for that - handy to know and might work for some of the rads.

At least one will need the radiator off so I was going to replace the TRV (slightly leaking) and also keen to know what I was getting into and if it was easy enough to get parts for. Had a look and seen the Danfoss 10mm TRV kit that claims to have 8mm reducing olive but some folk complaining they no longer included the smaller option, that so was thinking 15mm was a safer bet.

Watching this made me think I need the 8mm kit version

https://www.youtube.com/watch?v=XQn344ySG6s

[scottdm3]

If you replace the valve you will probably have to replace the tail into the radiator.
Might be time to fit a new radiator as it looks pretty old

[pistonheadforum]

Yeah it's an old radiator long due a replacement. Imperial sized so a bit of a faff.

mr momo, where did you get the replacement heads from?

Found these which I think are the ones I want but wondered if you bought them locally

https://www.amazon.co.uk/DANFOSS-DANFRAVL2950-Buil...

Also, is your a 10mm piping as it looks a fair bit thicker?

Many thanks

[Black_S3]

pistonheadforum said:

What would I be looking for? 15mm TVR with an 8mm compression internal reducer kit?

Thanks in advance

Essentially yes, 15mm trv then use a reducer like below if the existing nut/olive isn’t already a reduced 15mm.

https://www.traderadiators.com/trade-direct-pair-o...

The reducers can take a fair bit of practice to get to crack without buggering 8mm pipe so maybe not the wisest task to take on while many plumbers are on holiday/only doing emergency rate work.... in many cases the easier option can be soldering an 8-15mm reducer under the floor and bringing the pipes up in 15mm.

[Mr Pointy]

OP there don't seem tto be many 8mm TRVs but this Pegler one is described as 8/10mm:

https://www.pegleryorkshire.co.uk/EN/Brands/Terrie...
https://www.toolstation.com/pegler-terrier-3-trv/p...
https://www.bes.co.uk/pegler-terrier-3-trv-drain-o...

I'm sure if you ordered one from Toolstation & went to collect they'd let you open it to see if it has an 8mm adapter included.

[pistonheadforum]

Thanks - yes they do a 8mm/10mm version but could not find out if the 8mm olive was included anymore.

In the end got a few of these:

https://www.diy.com/departments/plumbsure-compress...