cold rad, TRV valve pin not operating correctly

[dacker]

Hi
I would be grateful if anyone could offer me some advice regarding
a cold radiator.
After turning the central heating on, all rads heat up except for one,
which stays cold even though i have opened up the TRV on the highest setting.

I have unscrewed the TRV top section, left it off the rad, then lifted the pin up with pliers,
the rad then heats up fine, then i have tested the TRV internal mechanism
and it seems to move in and out when i adjust the settings whilst its off the rad.

When i refit the TRV, turn heating off and then restart in the morning, the rad stays cold, it
seems the pin is either sticking down or the valve is not opening it up correctly, but i am not
sure.

What course of action do i have to take?
many thanks
Dacker

 

[IDCHAPPY]

I go for a replacement of the TRV, especially if the valve was made in 19 oatcake. 🙂

 

[Ermintrude]

Yep me toooooo. Or just leave head unscrewed. U could put some cooking oil around pin and move it in and out, whilst singing oke koke . This might help if not new trv.

 

[dacker]

I was hoping that i did nt have to fit a new TRV valve because i would have to drain the system. I will try the cooking oil first whilst singing ha. Many thanks for your kind advice

 

[Best]

Why not try to swap the TRVs head with another one in the house (if identical) & see if rad keeps working for a day or two?
Usually the metal body is faulty, I find, but some Trv heads do give trouble, especially Myson.

 

[JCplumb]

Yep me toooooo. Or just leave head unscrewed. U could put some cooking oil around pin and move it in and out, whilst singing oke koke . This might help if not new trv.

Is the cooking oil really necessary? I always thought it was the singing oke koke bit that fixed them...

 

[dacker]

Great idea. Thanks

 

[WHPES]

Whatever you do, don't pull the pin right out!

 

[stevetheplumber]

i found lots of the myson heads faulty they seem to be sprung loaded

 

[Best]

i found lots of the myson heads faulty they seem to be sprung loaded

The faulty Myson Trv heads are hard to turn their chrome nut because, as you say, they seem to be sprung loaded & put pressure against the nut. Also the Myson heads get brittle with heat & snap off if touched. Total junk.

 

[WHPES]

It's the Danfoss ones with the pins I find to be the worst for sticking. I have found the Pegler Terrier ones to be the best without getting the really expensive valves, though I have had the odd one leak.

 

[Best]

It's the Danfoss ones with the pins I find to be the worst for sticking. I have found the Pegler Terrier ones to be the best without getting the really expensive valves, though I have had the odd one leak.

I found the older Danfoss TRVs (the type with the clip to hold the head on) stuck inside & can't be fixed. You can buy glands for them if they leak though. The newer, fairly inexpensive Danfoss valves seem good, I thought, although the bodies are odd & few threads.
The Pegler Terriers are expensive I think & not great quality. A lot have stopped fully turning off. The similar Bulldog cheaper version seems to have identical body.
The Mistral TRVs are cheap & look okay. Decent lockshield in their pack.

 

[WHPES]

Our merchant has started stocking Altecnic Ecocal valves. Fitted a few but not been on long enough to determine durability.

 

[dacker]

Hi all
Quick update for you,
I raised the problem valve pin, lightly filed and lubricated it then closed it down, i then shut the rad in the other room off, then lifted the pin again till rad got hot and left pin up, then opened rad in the other room. Its worked a treat even with the TRV valve head back on, i left heating on for a while, then turned it off, let go cold then turned heating back on and the problem rad got hot again and its worked fine since, Many thanks for your kind replies

 

[SimonG]

Hi all
Quick update for you,
I raised the problem valve pin, lightly filed and lubricated it then closed it down, i then shut the rad in the other room off, then lifted the pin again till rad got hot and left pin up, then opened rad in the other room. Its worked a treat even with the TRV valve head back on, i left heating on for a while, then turned it off, let go cold then turned heating back on and the problem rad got hot again and its worked fine since, Many thanks for your kind replies

Always good when somebody takes the time to let everybody know how things turned out. 🙂

 

[Ermintrude]

You did sing oke koke though? Mods bit strict on plumbing protocol ?

 

[JCplumb]

You did sing oke koke though? Mods bit strict on plumbing protocol ?

He must have done as it is now working 😉

 

[Ru0907]

I've had the same problem before. I replace the valve. Bit of a pain draining down I know.