Bare with me, I’m just learning how the central heating and hot water (HW) work.

The house has an S-plan system so that’s two two-way actuated valves, one for HW and the other for central heating. The actuator on the HW valve is getting really hot, hotter than the pipe. I was wondering if the actuator continues to run whilst the valve is in the open position. It makes sense that it does as it seems to need to maintain the force in order to counteract the return springs that are used to close the valve.

It seems a bit of a fire hazard because the actuator’s seriously hot even without the valve head shroud on. Can anyone confirm if this is the case? That is whilst the pump for the HW is running and the HW valve is open that the actuator is and should continuously run? It won’t turn beyond the limits of the valve itself so presumably it’s just keeping the valve open for what could be hours (if the thermostat doesn’t reach the required temp).

So, that’s a motor that should be turning but not being allowed to turn, will it burn out? Should it somehow stop and lock into position when the valve is open but maintain enough force to continue to counteract the return springs. If that’s the case then there’s something wrong electronically. Perhaps it’s normal?

The way it works is that the motor is continuously energised while the heat or hot water demand is there. I’ve never noticed significant heat build-up (although don’t forget it’s going to be as hot as the circulating water).

If you want to troubleshoot then open the valve manually (little lever on the side), which will trigger the pump and boiler. If it still gets hot, it’s not the motor.

They do have enough current running through their internal micro switches to run a circulating pump but it’s not enough to make them warm.

If you’re in doubt, swap it for its friend or just replace with new head.