We have Drayton thermostatic valves on our radiators and I think some have become jammed and inoperable. They are quite old, maybe 15 years or so.
Can this happen to them? As a start I have removed the top portion of one of them, exposing the little pin, and simply cannot make that move up or down. Does this mean it has become jammed up and needs replacing? Is there a way of dealing with these by perhaps spraying with WD-40 or silicone to try and free it? If they need replacing does the radiator need draining?
Any help and advice most welcome on this. Thanks. John In limine sapientiae