Myson radiator valve - still very hot even at lowest setting

[claudeballs]

One of my radiators will not change temperature when the TRV is turned down or up - it's always boiling hot - even at the minimum setting, thus the room is always like an oven !!
I've taken it off (unscrewed it) and cleaned it i.e blew it and even hoovered it. Still to no avail.

All my other radiator valves (Myson II's) in the house are working fine. Can anyone suggest anything to help?

 

[tryitandsee]

Pin stuck in open position, unscrew it again and try pushing the pin down with the hoover nozzle and long nosed pliers to pull it back up up again, keep on doing that ans it should eventually free up.

 

[alan m 1974]

Dont really advice pulling the pin as it will properly just pull out all the way.Normally there stuck closed and a little knock with a spanner on the valve body frees it,is the actual trv head ok,if it is and its pushing the pin down when you turn it down,the trv must have gone inside,why not just turn the other end off,when your too hot and on again when you need it

 

[dal5band]

I think the pin is down for closed and up for open. Normally the pin pops up (as it's spring loaded) when you take the head off. Check that you can press the pin with a flat hard object and it should pop up when released. Do this a few times to make sure it works - a DROP of wd40 may help.

Seems the adjustment on your valve head may be off so that it is not pushing the pin down fully to close the valve. I think you can pre-turn the control to get the right adjustment before you replace it.
Balance the rad anyway by shutting down the manual valve at the other end.

 

[claudeballs]

Thanks for all your advice. I gave it a good clean, put a bit of WD40 on it and reseated it/screwed it back on.
Now working a treat.

Thanks to all.