Thanks, these look grand. One worry I had was a lot of these valves are £50-60 which would be too much to get one and find out it won’t work for me, but the ones you link are cheap enough to have a hit or miss once.
I’m not sure I need the 4 wire and I note they only come in normally closed. Part of me thinks I need normally open. This is based on a design choice I made which is to keep my home automation ‘transparent’ to manual intervention. If I switch off the automation I can still use the heating as it was originally intended. Not sure how far I will get with this before something prevents it, but it currently still works. Although thinking about it, unless I find valves which have a manual, mechanical override I would still need to power the relay (not difficult) to turn a radiator off.
Much like the thread linked by @vzorglub above I will most likely be using SOnOff relays with custom firmware, so I do still have the manual button to open/close the radiator. I suppose it just comes down to whether the valves will spend their time mostly open or mostly closed. I could mix and match. The bedroom will very likely spend most of it’s time closed, but the living room will probably spend most of it’s time open. The hallway I might just leave manual and open as “base heat”.
I also don’t believe I need the 4 wire for feedback because my heating system has a locked open radiator in the bathroom, so even if all actuators are off and it takes 3 minutes to open one, the heating will not be upset if I command it on before the valve opens. Also I don’t think I will actuate all of my valves, I’m going start by actuating the ones that cause me bother, in that rooms get too warm because I’m trying to heat one other room with the whole heating, but if I shut the radiator off manually that room gets too cold, triggers heating, but the heating can’t heat it. Stuff like that which I’m currently facing.
How sure are we that these will be a simple swap for a “normal” thermostatic valve? I am about to have my heating converted from oil to gas and the company doing the job is intending on putting in thermostatic valves, which I hate by the way, but I either let them put them in and swap them (they quoted something like £14 per valve) or I ask them to not put the actuator heads on the rads I want to automate.