thermostatic radiator valves

[andyv]

I've got a central heating system full of 30 year old TRV's.

Now and again I need to tap the pin to free off a valve, and I'm unsure whether some of the valves work correctly at all.

Is there any simple means of testing the valve or just the actuator?

If I decide to replace, does anybody have a particular recommendation?

I assume that the idea is that the valve senses the room air temperature and controls the water flow, and this can only be approximate if it's actually attached to the rad.

Thanks

[The Natural Philosopher]

Not really, other than when turned down it doesn;t burn your hand off in a warm room.

Pass!

absolutely.

Cheap and relatively ineffective, but better than the square rooot of bugger all.

Better is room stats and motorized valves. i.e.zone the whole thing.