Replacing wheelhead valves with TRVs

[flutterbye]

I'm hoping to replace existing old-style lockshield/wheelhead valves with TRVs. Just got a sample cheap TRV from toolstaion (link below) and the distance between valve and radiator is several cm wider than existing traditional valves.
So are most TRvs not a direct replacement for existing pipework with traditional lockshields? DOes that mean I need two ugly elbows to widen the pipework out to accomodate a TRV?

Any help much appreciated.


http://www.toolstation.com/shop/Hea...tic+Radiator+Valve+10+15mm/d230/sd2762/p80954

 

[alex444]

Do you mean that the valve "tail" is too long? between the rad and valve body?
I wouldn't recommend using toolstation trvs, you get what you pay for, not saying buy mega expensive ones but something mid range will last longer and possibly fit better.
I recommend the Danfoss RASc2 usually about 10 or 11 quid each but well worth it.

Alex

 

[muggles]

Should fit as a direct replacement, can you post a picture of the existing valve, I have a feeling I know where you're going wrong but without seeing it's hard to say for sure

 

[flutterbye]

Thanks a lot for the replies. I've got 3 images:

This one shows the trv with all the parts on the left and on the right is a new lockshield/wheelhead valve that I know for sure fits the radiator because I've fitted this before to other rads in the house.

http://i1224.photobucket.com/albums/ee377/flutterbye29/trv1Large.jpg


Next pics show the TRV at the bottom with regular valve at the top.
http://i1224.photobucket.com/albums/ee377/flutterbye29/trv3Large.jpg
http://i1224.photobucket.com/albums/ee377/flutterbye29/trv2Large.jpg

Unlike the regular valve, the TRV appears to have a 15mm compression fitting instead of a radiator thread although it does have what I think is an adapter. HOwever, with the adapter in place, I think the horizontal gap between rad and existing pipe that comes up vertically from the floor is maybe not wide enough. Certainly this TRV looks about 10mm wider than the regular valve.

Second (hopefully!) easy question is that the TRV shows 2 arrows. One points down where it would connect with the pipework and the other points towards the radiator. i.e. both arrows show flow away from the valve! Does this just confirm it is bi-directional? The poor leaflet that accompanies it says it is "With thermostatic head and reversible bi-directional body". DOes it all just mean it can be fitted at the flow or return side of the rad?

 

[hansthebear]

edit

drill a hole next to the pipe where it comes up from the floorboards and move it out a little bit

yes that means they are bi directional

 

[flutterbye]

Would there be a risk of drilling through the main flow or return pipe below the floorboard or moving the pipe and so causing a leak at the joint where it meets the main pipe below floorboard?

 

[denso13]

Just take it easy and don't drill too close to the existing pipe, finish the slot with a chisel/old screwdriver.

 

[carlsquires]

have you thought about trying to get hold of different tail?, ie ones that are supplied with other types of trv, would be a straight swap then, would save you the hassle of drilling floors etc. try asking a local plumber or merchants, sure someone will have some lying around.

 

[flutterbye]

Thanks again for all replies. I'm really down about this atm. Drained down the system this morning and still no heating or hot water due to buying a shed load of valves and non of them fitting very well.

It turned out that the TRV from toolstation fits well but given all the manual valves are seized on most rads I'm trying to replace them too but all the replacements I've tried so far don't fit. The one I'm trying to replace is the valve 3rd from the left with in the pic below:
http://i1224.photobucket.com/albums/ee377/flutterbye29/radvalves.jpg

The one on the left has a much large female thread which only the rads in the bathroom connect to. The one on the right is a trv which is no use (and doesn't fit anyway) and the one 2nd from the left is a 15mm compression fitting BUT amount you can push 15mm pipe into it is very small - much smaller than most compression fittings I've used before and also about half the size of the existing valve. For that reason it isn't a straight swap. Oh, the nut that comes with it seems very slightly smaller than the existing one since its a real struggle to get it onto the pipe.
This one, (the one second from the left) is also this bought from screwfix http://www.screwfix.com/p/all-chrome-angled-radiator-valve-15mm/89774

FOr the record here is the situation with the existing valve removed.
http://i1224.photobucket.com/albums/ee377/flutterbye29/radi_connection.jpg

Any help very much appreciated. I'm just glad its not winter !!!

 

[denso13]

Take out the existing tail from the radiator, remove the nut and olive from the pipe and fit the new valve complete with new nuts etc. Some valves are interchangeable but most aren't, as you have just found out. And there is far to much PTFE tape on your pics!!

 

[flutterbye]

Removing the old tails for a 30-40 yr old radiator isn't easy though!