Thermostatic radiator valves.

[Aquagility]

My seven year old house has a thermostatic valve on each radiator, but they don't operate effectively. If a rad. stays cold in a cold room it is necessary to turn it down to low and up again to hot - then the rad. heats up.
Do I need new valves, or what can I do to breath life into the old ones?

[tony1941]

I've had this happen. If you remove the adjustment bit of the valve (either unclip or unscrew by hand dependent on make) you will see a small brass pin sticking out of the valve body. This is what sticks down. I just pushed it down and pulled it up with pliers a few times, but with hindsight, probably a drop of WD40 would have helped.

[Aquagility]

Thanks, tony, I'll try that.
Were you born in 1941?

[tony1941]

Yes. It was ages ago! (in Liverpool)

[Aquagility]

Very good. I sailed out of Liverpool on the Yeoward Line 'Alca' in 1936!