I am trying to figure out how I can make my gas boiler smart and integrate with a Generic thermostat in HA, but I am unsure how to make the connections.
My boiler has 2 connections on the board (TH1 / TH2) that the manual says is used for connecting an external thermostat, that are currently bridged with a small cable between them closing the loop. I was thinking of putting a Sonoff ZBMINI (No neutral) between the connections and be able to turn on/off the heating and make the switch control the thermostat. However, I am unsure if the connections are powered already or if I should supply 230V to the connection.
I would appreciate if someone could firstly validate my thinking and also take a look at the manual give me some advice.
Personally, I think you should use a switch with so-called dry contacts to connect TH1 and TH2 together.
The “dry contacts” are completely separated from the 230V.
Could you please expand a bit on how this switch differs from the switch I have and how I would connect this up ? I am not really sure what a “dry contact” is to be honest
The sonoff you are suggesting using is switching 220v (or whatever you mains voltage is) Your boiler just just needs a switch which will connect th1 and th2, or disconnect them. So a relay across th1 and th2 will do it. Don’t put mains voltage across them, the magic smoke will escape if you do.
I don’t think you want 230V on contacts TH1 or TH2, because 230V can blow up your boiler.
Dry contacts are separated from the 230V, so you can connect the contacts to this switch with confidence, without destroying everything.
