Replacement TRVs

slipthru

I am wondering if someone can help me with identifying these TRV's and also know if I could just replace the TRV head and not the the valve as well? and if so what TRV head would I be able to use to replace it. 

Thanks in advance

ThisIsWeird

Replacement heads will almost certainly be available, but I haven't looked yet. Depending on your CH control system, you may even wish to consider Smart TRVs on the most commonly-used rads, to automate them for best efficiency?

Meanwhile, tho', it's worth you removing the heads and checking the actual valve for good, smooth operation.

Open the TRV head up to max - '5'. Grip the serrated chrome ring under the head and undo it anti-clockwise as you look down on it. If it's stuck, then either use an adjustable spanner on it, or grab the head body at the same time, and also turn this anti-c at the same time as you try and turn the chrome ring - it'll only move a few mm. Now, hold the chrome ring steady, and turn the head body clockwise a few mm. Then repeat - turn both the chrome ring and body anti-c. Repeat the repeat. 

Once the head is off, check the condition of the valve underneath, and the pin wot sticks out from t'middle.

Post a photo, please.

slipthru

Thanks for the reply, I have checked the pins and while most were stuck I've tapped them and they now move freely.

I'm in the middle of trying to balance the rads as my living room rad was not getting as hot as a bedroom one. So i'm unsure where I'll need working TRVs just yet, but definitely in the kitchen as it's tiny and often gets to hot. 

 

Albermarle

slipthru said:

Thanks for the reply, I have checked the pins and while most were stuck I've tapped them and they now move freely.

I'm in the middle of trying to balance the rads as my living room rad was not getting as hot as a bedroom one. So i'm unsure where I'll need working TRVs just yet, but definitely in the kitchen as it's tiny and often gets to hot. 

 

However when you balance the radiators, you need to make sure all TRVs are fully open.

ThisIsWeird

They look nice and clean, with no signs of leakage.
To fully check them now, get a teaspoon and place it over yer thumb - 'cos it'll hurt otherwise. Press firmly down on the pin, and note how it feels.
It should move smoothly, bottom-out with a firm thunk, and pop back up instantly when released - does it?
If so, what I would then do is to get some silicone grease, and smear it over the pin, pressing it firmly around where it disappears. Every time it's now activated, the silicone should help lube the seal inside, and keep it good.
The surf for new heads

slipthru

ThisIsWeird said:

They look nice and clean, with no signs of leakage.
To fully check them now, get a teaspoon and place it over yer thumb - 'cos it'll hurt otherwise. Press firmly down on the pin, and note how it feels.
It should move smoothly, bottom-out with a firm thunk, and pop back up instantly when released - does it?
If so, what I would then do is to get some silicone grease, and smear it over the pin, pressing it firmly around where it disappears. Every time it's now activated, the silicone should help lube the seal inside, and keep it good.
The surf for new heads

I have one that leaked when the plumber tried to free it, but it's not leaking anymore. The rest are all fine as in not leaking. How far should I be able to move the pin as it doesn't go all the way down? I've ordered some silicone grease today so will put that on when it comes.

ThisIsWeird

slipthru said:

ThisIsWeird said:

They look nice and clean, with no signs of leakage.
To fully check them now, get a teaspoon and place it over yer thumb - 'cos it'll hurt otherwise. Press firmly down on the pin, and note how it feels.
It should move smoothly, bottom-out with a firm thunk, and pop back up instantly when released - does it?
If so, what I would then do is to get some silicone grease, and smear it over the pin, pressing it firmly around where it disappears. Every time it's now activated, the silicone should help lube the seal inside, and keep it good.
The surf for new heads

I have one that leaked when the plumber tried to free it, but it's not leaking anymore. The rest are all fine as in not leaking. How far should I be able to move the pin as it doesn't go all the way down? I've ordered some silicone grease today so will put that on when it comes.

I think around 6mm or so - not a lot.
How it feels is important - smooth, and 'thunk'. Popping back up with no hesitation.
Give the top a good toothbrushing to get all dust and debris off before the sili smear.
Before you start balancing the rads, mark the position of each lockshield spindle (paper flag, or permanent marker) and then close them off clockwise, noting how many turns and parts turns each takes. You can then always return them to that position if it goes pear-shaped...

Looking at your pic of the head, it has '29' on its side - I wonder if that is the thread size fitting dia?

slipthru

Yes they seem to be popping up no problem. The couple that are not working properly I can do without a TRV on anyway.

All the lock shields were fully open. I closed them all on the radiators nearest to the boiler and then opened them a  half a turn, a quarter was not enough. Now the two furthest radiators finally feel hot instead of taking ages to feel warm. I still need to adjust a bit more but the flat definitely feels better over this cold snap.

ThisIsWeird

slipthru said:

Yes they seem to be popping up no problem. The couple that are not working properly I can do without a TRV on anyway.

All the lock shields were fully open. I closed them all on the radiators nearest to the boiler and then opened them a  half a turn, a quarter was not enough. Now the two furthest radiators finally feel hot instead of taking ages to feel warm. I still need to adjust a bit more but the flat definitely feels better over this cold snap.

In what way are two not working properly?

FreeBear

A wet finger or hand is no where near accurate to balance radiators properly. You need a thermometer in the feed and return pipes and adjust the lockshield to get a 15-20°C difference. The pump speed may need to be reduced if you can't get that sort of temperature drop.

Or if you do a search for "dual k type thermometer for pipes", you should find one for between £20 and £40. e,g, https://www.aliexpress.com/item/1005007018010511.html

slipthru

ThisIsWeird said:

slipthru said:

Yes they seem to be popping up no problem. The couple that are not working properly I can do without a TRV on anyway.

All the lock shields were fully open. I closed them all on the radiators nearest to the boiler and then opened them a  half a turn, a quarter was not enough. Now the two furthest radiators finally feel hot instead of taking ages to feel warm. I still need to adjust a bit more but the flat definitely feels better over this cold snap.

In what way are two not working properly?

Just the one that leaked from the spindle when the plumber tried to free it, I would prefer to leave that one as I don't want it to leak again and I have one in the front room, but I've moved the thermostat into this room as it's the coldest, as it has single glazed sash windows.