Faulty TRV??

[watkins73]

I've just moved to a new house and a few radiators don't seem to have any temperature adjustment. If i turn the TRV to off they turn off (cold) but as soon as the TRV is on (even if on frost protect) the radiators are on full and the rooms get too hot. How can i test the TRV's? Is the TRV head the clever bit or is the temperature sensor in the pipework (i.e. can i just replace the head and not have to drain the whole system). Any advice would be appreciated.

 

[ChrisR]

The head - first make sure they're all fixed firmly onto the body.

 

[watkins73]

Tried this last night. A couple were loose and i tightened them. Put all on frost protect setting and checked them this morning. 2 were cold so potentially fixed but 2 were still on full. Any more suggestions??

 

[Saveme22]

make sure the trv heads are in the fully open possition before tightening to valve bodies.

 

[watkins73]

Tried everything. Took all TRV's off. Set them all to 5. Put them all back on tight. All radiators still on full irrelevant of TRV setting.

 

[clf-gas]

take the heads off affected rads, take a pair of pliers and slowly slowly gental does it manipulate the pin.
careful now!!!!!!!!!!!!!!!

 

[watkins73]

If you mean does the pin move in and out then yes i've already tried that!!

 

[clf-gas]

then drain and replace. cheap little blighters these.

 

[watkins73]

DO i really have to replace the whole part or will just replacing the head work?? (i'm trying to avoid draining the whole system) Is the head the 'intelligent' bit or is it the body??

 

[clf-gas]

the head, but obviously like for like.

 

[watkins73]

i'll buy 1 new one and try that. If it works i'll get the rest. cheers for advice.