Sticking Westco TRVs

[letmedoit]

We have Westco TRVs on all the rads in our house which are over 20 years old (bar one Danfoss recently fitted with replacement rad). One or two of the TRVs have stuck shut occasionally, but have always freed off using the flat of a screwdriver method.

Having run the CH for a couple of weeks now this year, I have three rads that the TRVs are sticking shut every time the CH comes on. They do all free off easily enough with my screwdriver. All the rads will then quickly get hot and the TRV will regulate the temp. of the room in the normal way. Two are in bedrooms and are set around 3, one is in the bathroom and is set just under 4.

The system was recently drained (completely) for fitting the replacement rad and Fernox put in when refilled.

Are the TRVs likely to free off or is it time to think about replacing all these old TRVs with new ?

Thanks

 

[ALCPlumbing]

Try giving the pin a spray with wd40 and push it up and down till it is moving more freely.

 

[letmedoit]

I have already put a tiny blob of silicon grease on each pin and once the valve has opened the pins can be pushed down easily and pop back up straight away. I do press the pins 1/2 doz. times more each time I have freed the valve just to make sure.

I guess it must be the valve sticking to the seat ?