Fitting New TRVs

[Dave1UK]

So we have a total of 3 radiators upstairs and 4 radiators downstairs. They all have TRV valves, however only have about 3 TRV heads, rest are missing, headless.

I am looking at buying new heads with a valve set and replacing them.

I am a decent DIYer however just a bit concerned in regards to the potential current state of the olives that will be present and whether they'd be good enough for reuse and a swap. I've done a bit of research and removing the olive could potentially deform the copper pipe? (probably would with me removing it!) so then it would be an absolute headache/mess getting everything to line up/fit etc. If reusing I have read I should use PTFE tape? Is that advised or will the PTFE be of no use?

Am I also correct in understanding that the room with the thermostat doesn't need a TRV?

Also furthermore one of the bedrooms that has a radiator is a top floor extension. It is the coldest room by far, up to 4 degrees Celsius colder than every other room in the winter, it doesn't seem to retain heat well, I'm thinking of not using a TRV there either and just leaving it open as it would lag behind any other room regardless so would be counterproductive?

 

[endecotp]

You don’t want to fit the new heads on the existing valves?

 

[Dave1UK]

You don’t want to fit the new heads on the existing valves?

I would, however one valve has corrosion so that would need replacing 100%. The rest (no heads) I do try pushing down the valve pin before turning radiators on for winter and it's always stiff so it would probably be better to replace, don't think they've been replaced in like 10+ years.

 

[endecotp]

don't think they've been replaced in like 10+ years.

Blimey, how long do you think a valve body will last? I’d hope for several decades.

 

[drives]

If you use an olive puller tool, this shouldn't deform the pipe. I have this one and can recommend:

olive puller

Your considerations regarding top room sound reasonable. Does it get as hot though i.e. does the system need balancing. Furthermore, is this why the heads have been removed from some other radiators as they only just meet heat loss perhaps?

If you are doing some plumbing work anyway and replacing the valves is it worth looking at potentially upgrading the radiator in the cold room. Quite often the pipework doesn't need much if any modification (to go from a K1 to a P+, for example).

 

[Dave1UK]

Blimey, how long do you think a valve body will last? I’d hope for several decades.

Probably several decades, but who knows when these have been changed last?

If you use an olive puller tool, this shouldn't deform the pipe. I have this one and can recommend:

olive puller

Your considerations regarding top room sound reasonable. Does it get as hot though i.e. does the system need balancing. Furthermore, is this why the heads have been removed from some other radiators as they only just meet heat loss perhaps?

If you are doing some plumbing work anyway and replacing the valves is it worth looking at potentially upgrading the radiator in the cold room. Quite often the pipework doesn't need much if any modification (to go from a K1 to a P+, for example).

I've seen a few reviews and allegedly the olive puller is more likely to deform the pipe as opposed to other tools like a olive cutter/normal pliers to remove etc. I'm no expert just going based off what I've researched.

The top room is the 1st/2nd in the system to get hot in sequence so it gets hot enough and is balanced, just the room itself doesn't retain heat well, most likely down to crap insulation and given it only shares one shared wall? House itself is a terrace so all other rooms are good temp wise.

No clue but I haven't really bothered with it until now, rising energy prices so trying to get house ready and "efficient" with things that are DIYable. Will take a look at another radiator.

 

[foxhole]

Lots of online videos showing out to change valves without any drain down.

 

[Terry lambert]

TRVs work on room air temperature, so if that colder room isn’t getting warm enough the TRV will just stay open anyway.


If you’re changing the valve bodies, the existing nuts and olives are generally fine to reuse unless the pipe has been badly compressed or necked. I very rarely have an issue with them.


I wouldn’t use PTFE on the olive. The olive makes the seal, not the thread.

 

[Dave1UK]

Lots of online videos showing out to change valves without any drain down.

Indeed, not too worried about draining down etc. Just about the potential olive situation, i.e. reusing old olives -> removing old olives -> deforming the pipes.

TRVs work on room air temperature, so if that colder room isn’t getting warm enough the TRV will just stay open anyway.


If you’re changing the valve bodies, the existing nuts and olives are generally fine to reuse unless the pipe has been badly compressed or necked. I very rarely have an issue with them.


I wouldn’t use PTFE on the olive. The olive makes the seal, not the thread.

Yeah probably makes sense to not use a TRV in that case for the room.

Since posting have been watching more videos about valve changes. Yeah you're right about the PTFE, wrong advice from AI. Although plumbers seem to use Jointing Compound on the olive - on the pipe, slide the olive on if replacing and then a bit over the top as well for a better seal? Think I'll buy a pot of Fernox Water Hawk Jointing Compound (non-toxic one) and if reusing the olive dab a bit over it before tightening?

 

[ericmark]

Here I did all mine together, so did drain down, in mothers house, only changing one, and under the carpet was a tiled floor, so I just got the carpet washer at the ready, did it quick and sucked up the water after, actually, very little came out.

As to the TRV heads, the electronic versions are designed to replace many makes, so the likes of the eQ-3 heads (I paid £15 each) come with adaptors and auto-adjust to the pin travel, and show if under or over travel or stuck, so easy enough to retro fit. They come in a number of different flavours, from simple at the TRV head programming, to bluetooth so can use phone, to Wi-Fi so can even change when away from home, and linked either to wall thermostat or some central hub.

There seems to be just one drawback, for some reason it seems it was common to fit radiators on outside walls, which means the TRV is against an outside wall, so registers a temperature lower than the real temperature until the thermal movement of air has been established. So when linked to the boiler, they can fire the boiler prematurely. But once the thermal exchange has been established they work A1.

The result is I am not sure if worth the money to monitor from an internal wall? The Kasa head I have, will connect to sensors on the wall, without also connecting to the boiler, the Drayton Wiser however you designate a room, so the wall thermostat does control the TRV, and also the boiler as well. Depends on the make fitted as to what they can do.

I refer to near enough engineering, we could fit loads of wall thermostats and TRV heads, and have a perfectly controlled home, but the gains are limited, so I have three wall thermostats, four machanical TRV heads two motorised valves, five bluetooth TRV heads, four wifi TRV heads not linked to boiler, and one TRV head linked to boiler. Not perfect, but near enough for what I want.