Hmmm, can't figure this one out.

I have a zone on the top floor of my house with 4 actuators however which simply won't kick their radiators into life. The radiators all work fine with TRVs on and the actuators all work when put on other radiators but they will not switch the radiators on and off on the top floor. I wondered whether it might be because they aren't picking up the signal from the controller but they do seem to change when I change the temperature settings, they just don't open up as required.

I've changed all the batteries, deleted the zone and recreated it and tried with just one actuator, all without any joy.

Any ideas or thoughts very welcome!