Trv valve doesn't look right

[Ramprat]

Hi,

Does anyone recognise this valve?

It had the same thermostatic head on it as the others in our house but the valve looks totally different, the others were Drayton types i think.

This rad is getting very hot no matter the setting, I took it apart thinking the pin was jammed but I don't think that middle bit is a pin, if it is its jammed tight as no give at all when wiggled with pliers.

Any ideas? I'd rather not have to replace the valve now as having some work done after Christmas which will require draining the system so do really want to do it twice but the room the rad is in is our bedroom and its so hot in there by the evening so need to try and fix, atleast temporarily.

Thanks

 

[pejoli]

Hi,

Does anyone recognise this valve?

It had the same thermostatic head on it as the others in our house but the valve looks totally different, the others were Drayton types i think.

This rad is getting very hot no matter the setting, I took it apart thinking the pin was jammed but I don't think that middle bit is a pin, if it is its jammed tight as no give at all when wiggled with pliers.

Any ideas? I'd rather not have to replace the valve now as having some work done after Christmas which will require draining the system so do really want to do it twice but the room the rad is in is our bedroom and its so hot in there by the evening so need to try and fix, atleast temporarily.

Thanks View attachment 46603View attachment 46604

Well that's weird - I was about to post about a similar problem, and I have exactly the same valves - all of mine have bulldog heads on them, so I assume that's the brand.

My symptoms are that I can turn the heads to 0, and the rad goes off (and I can push the 'nub' in and out ok) , but anything from '*' onwards is full-blast. Same problem ? It seems to be the same on every rad in my house.

 

[Timmy D]

Yes that’s the pin. Hit it with the persuader.

 

[Basher]

Or if you've got a lockshield valve on the other end of the radiator, you could turn that down (count the amount, so you can get it back roughly where it should be for balancing after Christmas).

 

[SimonG]

Pegler bulldog valve.

 

[Ramprat]

Well that's weird - I was about to post about a similar problem, and I have exactly the same valves - all of mine have bulldog heads on them, so I assume that's the brand.

My symptoms are that I can turn the heads to 0, and the rad goes off (and I can push the 'nub' in and out ok) , but anything from '*' onwards is full-blast. Same problem ? It seems to be the same on every rad in my house.

Mine doesn't move at all tried small hammer and wd40 but no joy going to try large hammer next ha ha.

Could you post a picture of yours so I can see how high the pin should be, also have a theory based on some info id seem else were that maybe the pin is to short for the head, either due to wear or incorrect head type, that might explain why when you turn yours up past 1 its full on as the pin rises to far? Its only a guess to be honest but seen elsewhere a couple of people have put small magnets ontop to act as an extension and it solved the issue but that was a Hive thermostatic head, don't know if that helps?
[automerge]1607428495[/automerge]

Yes that’s the pin. Hit it with the persuader.

Thanks good to know I'm whacking the right thing and going in the right direction in trying to free the pin, was just concerned that it might not be a trv and that it wasn't a pin before I went yanking it with pliers to try and free it up

 

[steadyon]

pejoli:
1. the TRV senses the temperature of the air in the room, not the temperature of the water in the radiator.
2. As the room air temperature rises to meet the temperature set on the TRV, the valve gradually closes. This restricts the flow through the radiator, and the amount of heat transferred to the room, until it closes.
3. The temperature of the water in the radiator, and hence its surface temperature, will only gradually decline as the valve closes, because the heat is being lost to the room. The temperature at the flow side of the radiator will remain virtually the same as the boiler flow temperature until the valve closes.

 

[pejoli]

pejoli:
1. the TRV senses the temperature of the air in the room, not the temperature of the water in the radiator.
2. As the room air temperature rises to meet the temperature set on the TRV, the valve gradually closes. This restricts the flow through the radiator, and the amount of heat transferred to the room, until it closes.
3. The temperature of the water in the radiator, and hence its surface temperature, will only gradually decline as the valve closes, because the heat is being lost to the room. The temperature at the flow side of the radiator will remain virtually the same as the boiler flow temperature until the valve closes.

Thanks for the detailed response!

This is how I understood it, however, none of my TRVs ever seem to close, no matter what the air temperature of the room, and how far down I turn the head - unless I turn it all the way to '0'. For example, the stat is in the hallway which is a bit drafty, so always colder than the front room. yet if the air temp is 19 degrees there, and I run the heating. the front room radiator TRV is always open, even if it's set to '*', or even lower (which I thought would close if > 7 degrees or so). I've taken the stat into the front room (it's a Hive detachable one) - same result. And it's the same for all 12+ TRVs throughout the house (all the same bulldog make)

I wouldn't have thought that all the heads could be faulty - though they are probably 15+ years old - and the pins aren't jammed as I can turn them on/off mechanically by turning the heads, and push them in with my thumb (just about - a lot of muscle required, and I wouldn't be able to do it if they were pointy-er) - so I'm really confused.

Possible tangent, but I bought a cheapo electronic trv yesterday (too tight to spend £50 on a hive one!) - mainly so I could isolate the bedroom so the heating doesn't come on there until after 10pm, but also to see if it could rule out the faulty trv idea. Unfortunately it doesn't seem to work - I don't know if the mechanical resistance on the pins are too high for it, but it doesn't close them either after it's calibrated itself - and tried it on a couple of different radiators with same result. Don't know if that's an indicator of the problem here, or just quality control issues at screwfix
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Mine doesn't move at all tried small hammer and wd40 but no joy going to try large hammer next ha ha.

Could you post a picture of yours so I can see how high the pin should be, also have a theory based on some info id seem else were that maybe the pin is to short for the head, either due to wear or incorrect head type, that might explain why when you turn yours up past 1 its full on as the pin rises to far? Its only a guess to be honest but seen elsewhere a couple of people have put small magnets ontop to act as an extension and it solved the issue but that was a Hive thermostatic head, don't know if that helps?
[automerge]1607428495[/automerge]


Thanks good to know I'm whacking the right thing and going in the right direction in trying to free the pin, was just concerned that it might not be a trv and that it wasn't a pin before I went yanking it with pliers to try and free it up

Mine doesn't move at all tried small hammer and wd40 but no joy going to try large hammer next ha ha.

Could you post a picture of yours so I can see how high the pin should be, also have a theory based on some info id seem else were that maybe the pin is to short for the head, either due to wear or incorrect head type, that might explain why when you turn yours up past 1 its full on as the pin rises to far? Its only a guess to be honest but seen elsewhere a couple of people have put small magnets ontop to act as an extension and it solved the issue but that was a Hive thermostatic head, don't know if that helps?
[automerge]1607428495[/automerge]


Thanks good to know I'm whacking the right thing and going in the right direction in trying to free the pin, was just concerned that it might not be a trv and that it wasn't a pin before I went yanking it with pliers to try and free it up

Here's mine - with a usb

Mine doesn't move at all tried small hammer and wd40 but no joy going to try large hammer next ha ha.

Could you post a picture of yours so I can see how high the pin should be, also have a theory based on some info id seem else were that maybe the pin is to short for the head, either due to wear or incorrect head type, that might explain why when you turn yours up past 1 its full on as the pin rises to far? Its only a guess to be honest but seen elsewhere a couple of people have put small magnets ontop to act as an extension and it solved the issue but that was a Hive thermostatic head, don't know if that helps?
[automerge]1607428495[/automerge]


Thanks good to know I'm whacking the right thing and going in the right direction in trying to free the pin, was just concerned that it might not be a trv and that it wasn't a pin before I went yanking it with pliers to try and free it up

Here's mine, with a usb for scale

 

[pejoli]

Bump - Any thoughts on my non-functioning TRV heads from anyone ?

 

[ShaunCorbs]

Swap the whole valve

 

[pejoli]

Swap the whole valve

Yeah, I was worried that might be the answer - just seems odd that all 12+ of them seem to have the same problem (are there dodgy chinese knock-offs ?)

 

[ShaunCorbs]

Yeah, I was worried that might be the answer - just seems odd that all 12+ of them seem to have the same problem (are there dodgy chinese knock-offs ?)

could be cheaper so maybe

 

[ShaunCorbs]

I only fit danfoss rasc2

 

[Ben-gee]

RasC2 for normal rads, rasD for posh ones!

 

[king of pipes]

Not a very reliabe valve get em swapped Honeywell Valencia VT117 - 15 is my choice you can buy a rad pack for around £15 . Kop

 

[Ric2013]

I had Pegler Terrier 2 TRVs in my own house and have had them come on at 12-14°C when on * setting which should be 'approximately' 7°C. The idea that setting 1 is 11-13°C (which I would think ideal for a bedroom) was laughable and they were consequently often set to * setting or just below.

I also have a friend who has an old Honeywell I fished him out of a skip back in the days when I was working as a labourer. It has the wrong head by the looks of things and maintains the right temperature somewhere between frost and off setting. We put a dot on it where the setting seemed to be about right. It's still there and working perfectly, just looks a bit odd. Perhaps this solution might be what you want, at least on a temporary basis?