Radiators on full with TRV set to OFF

[d000hg]

A couple of radiators in our house seem to come on full whack even with the TRV set to 0/*. We've only been here since April and this is the first time it's been properly cold so I cannot say if it's a new development.

They look to be fairly new TRVs. One of them the other end of the radiator has a manual valve I just shut off but the other is a huge one in a room we do not use.

Is it likely they have failed, or are just set up badly and nobody ever noticed - previous owners appeared to use the heating a lot so perhaps didn't care!

 

[ianmcd]

some TRV valve sensors are prone to failing, post a pic of which ones you have , some its just the sensor that is loose.

 

[d000hg]

Will do. I had one that tore itself apart once... the actual valve had corroded in the 'out' position (on/off?), as the TRV tried to push it in it instead broke itself off the fitting!

 

[mcmoby69]

most trv's are plastic, they dont like heat or sunshine and the plastic deteriorates. manufactured to fail. pin could be stuck under the valve, head could be jacobs.

replacements heads may be available, new valves definitely available.

 

[d000hg]

We look to have a job lot of them; as I recall the heads are easily removable with no mucking about with water supply?

So swapping two between a 'faulty' and a 'good' one should clear up if the issue is with the valve or the TRV... or at least narrow the number of possible issues.

 

[mcmoby69]

heads are mechanical as are the bodies. both can fail. belt and braces change them both.

 

[Daveydub]

heads are mechanical as are the bodies. both can fail. belt and braces change them both.

Good advice but swapping a known working head will be quick & easy. While head is off press down on the pin and check that it moves easily. make sure is screwed fully down or retaining ring is pushed home.

 

[mcmoby69]

sometimes its cheaper to buy the full valve rather than the head on its own. drain the system swap the valves, refill job done.