Integrating a Gas Wall Heater

Hardware
1

I have a two-sided, Willams brand “High Efficiency” gas wall heater with a simple wall themostat (see below) in a rented apartment.

I would like to integrate the furnace in Home Assistant. Ultimately, all I need is On/Off functionality because I have temperature sensors elsewhere throughout the apartment.

Keeping in mind that I would like to keep it simple and cannot make any permanent modifications to the apartment, what are my options?

Thermostat Unit

2

I see two solutions for that:

  1. Open the thermostat and solder a relay to the right contacts, this type of thermostat are probably on/off controllers. Then control this relay via Z-Wave, WiFi or whatever you fancy.

  2. The furnace has some electronics itself and is connected to the thermostat. So you can disconnect the thermostat wire and connect your relay directly there. The benefit is there might be power available for your devices. But most furnaces have more than one input channel for control and that way you don’t have to remove anything, just connect the relay. The furnaces’ manual will provide you with the type of connections.