Living in an old building with radiators that are connected with your neighbors above and below introduces (major) issues if you want to install a thermostatic radiator valve - ie. the pipes will need to be frozen - very costly, plus it is not an ideal season to do this (winter).
I wanted to come up with a cheap solution so that the knob could be turned open/closed via wifi.
Solution: use a valve actuator, normally used for gas/water/gardenhose. These have high torque motors which will work for my radiator.
This is a wifi controlled valve, running on Tuya, that is great, as these can be flashed with tasmota, which ofcourse, I did
Installing introduced other problems, as the mounting clamp was just too short, I had to create a mounting bracket in tinkercad to create a rigid "frame" where the clamp could be inserted into.
Then I had to remove the existing knob and created a lever to replace it.
Printed them both on my 3d printer (after many iterations )
The end result is a frankenstein-like apparatus, but it is out of sight and (most importantly) it works :
Here, ofcourse, node-red comes into action!
With the valve now running on tasmota, I created mqtt-based flow and with the help of homebridge-mqtt, added it to homekit, added it to my daily heating flow (my other radiators have z-wave driven thermostatic valves, this was the last one to "automate")
The valve opens 90 degrees, which is enough to heat the radiator. Next step will be to have some esp based temperature reading and open/close the valve when needed