This solution looks excellent! Came across it while trying to find Zigbee TRVs (for UK).
I like the idea of basic actuators controlling the radiators.
I’ve got two questions, please.
What throw is required from the actuator? I’ve seen some that have 3mm. Is that a correct amount? (Just regular Drayton TRVs on the rads at present)
Secondly, is any type of PID control easy to implement? Rather than just simple on/off at a given temperature? (I’m no expert at this, so I’d need a fairly user-friendly solution!)
Thank you 
