Universal TRV heads?

[VickyBH]

Some of the TRV heads in my home are old and don't work very well anymore. Is there any universal TRV head that fits any make? If not, will the same make of TRV definitly fits one another? Mine are made by Danfoss but there is no part/model number on it.

They all look like this


thanks.

 

[ianmcd]

This is your one , you can only use like for like with yours, some are interchangeable but yours is not, the sensor is silly money if you have a few that you want to change would be cheaper fitting new complete valves
https://www.ebay.co.uk/itm/New-Danf...312799&hash=item23a985be67:g:cRwAAOSwtgFbj-rg

 

[VickyBH]

That sensor head is almost the same price as whole set of valve for some brand. I prefer to change the valve too but the whole system is imperial not metric. I'm happy to get radiators too. What kind reducer/adaptor do I need for connection from imperial 3/4 pipe (cast iron) to 15mm valve?

 

[ianmcd]

Post some pics of your actual set up

 

[VickyBH]

We have communal heating in the building and the system currently drained off. The pipe are cast iron. This is a typical set up of radiator.



All TRV valves look the same. There are two types of locksheild valve.



It looks like there's tread on pipe, is that possible?

 

[ianmcd]

Buying that sensor head will work , but changing the valves is a different thing, not really a diy job

 

[muggles]

That sensor head is almost the same price as whole set of valve for some brand. I prefer to change the valve too but the whole system is imperial not metric. I'm happy to get radiators too. What kind reducer/adaptor do I need for connection from imperial 3/4 pipe (cast iron) to 15mm valve?

Beware cheap TRVs - they're cheap for a reason and on a communal heating system the last thing you want is the hassle of having to change them again in a couple of years.

If I'm reading your Vernier correctly, your steel pipe is ½", not ¾" - steel pipe is sized on its bore, not its outside diameter, and ½" steel pipe is about 21mm o/d.

Couple of options - either use ½" female iron to 15mm compression adapters and a short length of copper to adapt to "normal" valves (but you'll have to move all the radiators up the wall about 50mm) or buy new valves to fit the existing pipe. New valves to fit will be slightly harder to get hold of, but will mean you don't have to sod around moving all the rads.

As Ian suggests though, you're probably better off getting someone in to do it for you. That way it's not your fault if there's a leak when it finally gets filled up again

 

[VickyBH]

Beware cheap TRVs - they're cheap for a reason and on a communal heating system the last thing you want is the hassle of having to change them again in a couple of years.

If I'm reading your Vernier correctly, your steel pipe is ½", not ¾" - steel pipe is sized on its bore, not its outside diameter, and ½" steel pipe is about 21mm o/d.

Couple of options - either use ½" female iron to 15mm compression adapters and a short length of copper to adapt to "normal" valves (but you'll have to move all the radiators up the wall about 50mm) or buy new valves to fit the existing pipe. New valves to fit will be slightly harder to get hold of, but will mean you don't have to sod around moving all the rads.

As Ian suggests though, you're probably better off getting someone in to do it for you. That way it's not your fault if there's a leak when it finally gets filled up again

The threads on TRV and lock shield valve connecting to rad tails are 3/4 imperial so I just assumed the iron/steel pipe is 3/4. I think you are right the pipe can't be 3/4. Not only the vernier reading is 21mm-22mm OD, the nut on rad tails are considerably larger than the nuts on pipe so pipe thread can't be 3/4.

I have done my kitchen and utility plumbings myself during a refit but they were new installation plumbing and no fiddlings on old pipes. I feel less confident about this one (what if it's not 1/2 but some strange size thread?) because having a leak means it's not just my flat but involves whole building's heating. Would this be a time consuming job for plumbers (replacing 7 set of rad valves?).

I was looking at screwfix deal buy radiators and get free valves. Is this valve ok? https://www.screwfix.com/p/drayton-rt212-white-chrome-angled-trv-lockshield-15mm-x/679hg ?

 

[ianmcd]

We have communal heating in the building and the system currently drained off. The pipe are cast iron. This is a typical set up of radiator.

They are definately not cast iron

All TRV valves look the same. There are two types of locksheild valve.

No all Trv valves are not the same and there are a lot more than 2 types of Lockshield valve

As already advised get someone who knows what they are doing