Hi all,

I’ve got a sticking Danfoss control valve. The central heating comes on and then stays on as the valve sticks open.

I can reset it manually by moving the little metal tab back and forth a couple of times to unstick it but its happening more and more often.

Replacement actuators aren’t particuarly expansive at less than £30 but I’m wondering if anyone has managed to strip and clean the actuator rather than replacing it. Main reason for doing this is that the current one is nicely terminated and the new one would just be bare wires that I’d then need to terminate myself

Ta

Rich

It’s the microswitch that’s sticking. You could dismantle the valve and solder a new switch in, but having done it once I won’t do it again.

Budget about an hour of your time, a fir amount of faff with springs and screws complete with no guarantee that it’ll fix the problem (as the motor wears the spring loses the ability to wind the valve closed too).

Replace the head would be my advice…

As above, not worth the effort for the cost IMO.

If the same model is available, just change the head so you don’t need to drain the system and do any plumbing.

Thanks

I can just replace the actuator, no plumbing required, just need to wire up the new one

It is worth checking that the mechanical part of the valve is moving freely with the motorised part removed,
Sometimes if the system has low inhibitor the limescale can lead to the valve becoming stiff when operated, holding the switch closed when power removed, causing the heating to run on.
Had a couple of these in the past.

ours gets replaced every few years under the Scottish Gas maintenance contract. We get told it is a consumable part..