TRVs

[twinkydrip]

I know this is basic for most of you out there but can you please advise me as to why when I turn the TRVs in the bedrooms in my house to zero or the frost sign there is maximum output of heat from the radiators!! How can I turn the heat off on these radiators? Are all these TRVs faulty or does the system need balancing? Please help.

 

[aggis]

Trvs are faulty, prob the head has gone, some makes you can get just a replacement head, but prob cheaper getting & fitting complete trv.

 

[Toddyplumb]

They arn't just loose on the valve body are they ?
Faulty TRV usually will not give any heat !

 

[aggis]

Faulty TRV usually will not give any heat !

If wax cartridge in trv head gone , won't shut it off.

 

[Toddyplumb]

Yes , Ok if it has burst , I agree . I have never seen one go that way but OK

Just as an add on ; many years ago we were commisioning a system 8 trvs . We normally flush etc with the heads off and fit the heads at the end with nice clean hands .
One of the lads had put all the heads on top of a double convected rad for safe keeping Every head had overextended its capsule , 8 new Trvs required !! They dont like sitting on top of a rad at 80 deg

 

[fuzzy]

trvs dont turn off, they just go to cold, but if the rooms cold?? guess what they turn on. they are not on and off valves

 

[Toddyplumb]

Of course they turn off . Past frost protection (then sometimes past the stop) to off . Its down that far that the capsule is inoperative
Granted that is not how they operate in normal use , but they have an off.

 

[Scottley]

British gas ones have an off but all the ones i have come across need the special cap put on to turn them off completely

 

[Gray0689]

Of course they turn off . Past frost protection (then sometimes past the stop) to off . Its down that far that the capsule is inoperative
Granted that is not how they operate in normal use , but they have an off.

Yes I Agree with this

 

[tamz]

British gas ones have an off but all the ones i have come across need the special cap put on to turn them off completely

Most of the decent ones have a positive off.

 

[GrahamM]

TRV's in my house isolate completely. Also took a friends rad off the wall last week by isolating TRV and lockshield.

 

[Dotty]

TRV's in my house isolate completely. Also took a friends rad off the wall last week by isolating TRV and lockshield.

oooooooh you're brave Graham! I was removing rads in parliament buildings in belfast for the rooms to be redorated..... Or rather I left it to my apprentice......

as we were getting in the van I asked if he'd stuck female iron caps over the valve ends just in case the valves let by. No need he replied. TRV's and lockshields are holding ok. I dragged him out of the van and back up to the 3rd floor where a couple of puddles (water, not our esteemed administrator!) were collecting.

Yep, trvs turned to frost setting, cold day and windows were open.

Anyway, capped off the valves, mopped up the water and he went home with a large boot print on the back of his strides!

 

[tamz]

We all learned that one the hard way. Even still cap the ones with the supposed positive off as i don't trust them.

 

[Scottley]

Thats what i meant, i only ever seen the British gas ones with a proper off and that was last week. Still put a cap on them though

 

[GrahamM]

To be honest Croppie I never gave it much thought about the TRV failing. Not had a mishap so far, but good tip about capping off.
Will remember that for future. Cheers!