Good luck with your future apartment customizations!
Good luck with your future apartment customizations!
Though in reality many landlords don't mind as long as you know what you're doing and return it to how it was. Just a problem if you get a jerk landlord.
Penalties would depend on the adjudicator's opinion of the damages and risk.
Usually it's just acting as a simple relay (on-off switch) so there's two physical wires.
I've got my Hive thermostat running great with various Bosch and Vaillant boilers. And it works great with HA.
Some newer boilers have 12V "smart" controls but still expose 230V "dumb" call for heating pins.
Vaillant has a proportional signal as well, and that thing in my old home was 30 years old... [1]
[1] https://www.mikrocontroller.net/topic/126250?page=single
Also, if you read this far, are you German or something? you can just do things. which OP seems to know. And even if the landlord came and saw the apartment as long as the new thermostat isn’t neon orange, he isn’t going to notice and even if he somehow noticed you would just gaslight him and say no that’s how it’s always been and how the hell is he gonna escalate past that? And why would he if the new thermostat is more expensive and has better features?