Hot water is flowing into radiator, but the radiator is cold

[JackFrosty]

I'm trying to figure out why my radiator isn't working. The input pipe is nice and hot.

Hot was is definitely flowing past the temperature controller; there is a T shaped pipe which connects directly to the two (is "wings" the right word?" that feels warm to the touch.

However the wings themselves are barely heating up at all. What do you think could be causing this?

 

[Inky Pete]

You can't be getting a flow of hot water past the thermostatic radiator valve - just because the pipe immediately beyond it gets hot means very little, it'll get hot there anyway simply by conduction of heat through the metal of the valve.

The temperature control pin in the TRV might well be stuck down. Take the top of the valve body off (there should be screw ring just below the plastic temperature control) - don't worry, you're not going to leak water anywhere! You should then see a metal pin poking up vertically from the centre of the valve. Grip the pin with a pair of pliers and gently pull it upwards, it should only move a few millimetres.

Then, with the top of the valve body still off, see if your radiator gets warm.

 

[JackFrosty]

Thanks, I'll give that a try; but I have a metal temperature control (drayten trv 4).

Does that make any difference?

 

[Inky Pete]

No difference at all.

Just unscrew the silver ring below the white plastic bit and the top will come off to reveal the pin.

 

[JackFrosty]

Thanks!

 

[Agile]

Have you looked at the FAQ on this site and done the "bucket test" ?

Tony