The fridge door sensor in G1 is an ESP32-S2.

If there's a fault, unplug the power cable at the wall (under the first aid kit) to stop it running. If it breaks off the post that holds it onto the door can be removed with a 5mm wood screw.

Software and 3D printed parts: https://github.com/edinburghhacklab/fridge-door-sensor

The 3D printed parts for this are:

• sensor mount (on the fridge)
• post (on the door)

The sensor is a standard end stop limit sensor with the connector removed and some resoldering to align the holes properly: