Sorry - wasn't being clear. The old Y plan motorised zone valves (water and radiators)and boiler are controlled by node red via relays. The radiator valves have thermal actuators that are PWM'd by node red to give me proportional control. The whole system does need node red running and I know I'm going to regret saying this but I've found NR 100% reliable! The only times it wasn;t was during development when I messed up some 'trivial' change that I hadn;t tested properly. There is a watchdog system running that cuts the power to the heating if node red goes off the rails - better than leaving the boiler turned on. It hasn't been needed - yet!
Re - the motorised valves. The quietest ones I found were from Conrad and were self standing (no wireless). My intention was to convert them to mysensors 2.4Ghz. They were very quiet on the bench but varied from slightly noticeable to very annoying depending on which radiator they were mounted on. They would be fine in a living area but not in a sleeping area. They were the 2nd or 3rd type i tried. After that I made the decision to go with thermal actuators.
