Valve not shutting properly

[mjombly]

Hi, I have one radiator out of 12 in my evohome system that doesn't seem to be closing so the room is overshooting. It's one of these which I'm struggling to identify:

https://photos.app.goo.gl/Jtumb2btViL8Ri4UA

I've changed the Hr92 to Stroke 1 mode and made sure it's screwed on tightly.

I planned to try screwing the pin part down a bit but it's an 8 sided fitting and seems to fall between my 10mm and 11mm sockets in my socket set and I don't want to mess it up with pliers if it's not going to help?

Any advice gratefully received!

[DBMandrake]

Can't be sure because a lot of valves look very similar, but those look like the Peggler Bulldog valve bodies I used to have in my system.

It's the middle valve in the following post, flanked by two Valencia's:

https://www.automatedhome.co.uk/vbul...ll=1#post38132

If that's what they are then yes, after mine were a year or two old they started having difficulties not closing properly even in Stroke 1 mode. A combination of the rubber washer going hard and the pin corroding inside I think. Just not a very good quality valve.

I replaced them all with Valencia's. Sounds like yours needs replacing too.

Don't bother trying to turn the hex with a spanner, you won't be able to screw it down any further and if you unscrew it the valve will fall apart.

[mjombly]

Thanks DBMandrake, I'll get the valve swapped next time we have a plumber out to service the boiler.