Stone cold single rad

[mike004]

Bungalow. I've just moved in. Radiator in the kitchen is stone cold. All other rads/CH/water work fine. The problem rad is the one nearest the boiler, but I'm not sure if its actually the first or last in the chain.

Lockshield valve pipe (nearest boiler) = cold

TRV side (away from the boiler) = red hot

I am a total newbie, but am guessing that TRV side is IN and lockshield side is OUT.

Possible plans of action:

1. Bleed the rad? But the rad is stone cold all over.

2. Stuck TRV? I removed the TRV cap (to clean off spilled emulsion) and noticed a pin/nipple -- how do I check if this is stuck and/or unstick it? There is no way I can expose the pin as far as I can see.

3. Lockshield valve. Does this need changing?

Thanks for any help.

Mike

 

[ChrisR]

CHeck the lockshield valve isn't CLOSED! You'll have to get the plastic cap off to expose the shaft you need to turn.
And check that the pin on the trv body springs up and down. Down is off, and they do stick. Some judicious wiggling/hitting often frees them.

 

[mike004]

>CHeck the lockshield valve isn't CLOSED! You'll have to get the plastic cap off to expose the shaft you need to turn. <

Right, will do.

>And check that the pin on the trv body springs up and down.<
Pin on the TRV body? There was a metal pin/nipple visible in the pipe when I took the TRV cap off. I poked it with a screwdriver. It didn't "spring" at all -- it seemed to be a welded part!

>Down is off, and they do stick. Some judicious wiggling/hitting often frees them.<

How do I wiggle/hit something that is in the pipe? I can poke with a screwdriver, but not much else.

Thanks
Mike

 

[ChrisR]

It isn't IN the pipe, it's in the rad valve, which is the bit below the head. It gets pushed down by the head. Yours is stuck. Try poking with a small screwdriver, whack the side of the valve with a screwdriver handle, etc.

 

[mike004]

Took the TRV cap off. The pin is OUT.
Turned the lockshield 1 turn anti-clockwise.
The faulty rad came on full blast -- seems like trapped air is not the problem and it doesn't need bleeding; also it would seem the problem rad is No. 1 in the chain -- but all other rads were cold!

How can one problem rad unbalance the whole system so spectacularily?

Turned the lockshield CW half a turn. It was a mild night so I wasn't able to run the CH much, but early indications are that all rads appear to be working OK. It may be psychological, but the rads all appeared to be hotter than usual -- could this be due to rad No. 1 being "opened up"?

Mike