OpenMarine

Hi,
From now on me and my wife will live aboard one or two nights a week, all year around. 
We normally keep the boat in the water during winter but living aboard requires more than the usual 5 degrees Celsius to be comfortable. In order not to waste more energy than necessary I was thinking of a way to control our electric heater with the pi. Ideally it should be possible to remotely bring up temperature to 20 degrees a couple of hours before we get home. 
The heater is currently controlled by a bi-metal thermostat that in turn pulls a relay that switches on the heater. Replacing this circuitry with something else will not be a problem. 
Any ideas on how to accomplish this?
I run OpenPlotter 3 on rpi4 4gb 64-Bit
Cheers,
P

Use a shelly and the shelly plug-in. You'll also need a way to get environment.inside.temperature into SK. I used Ruuvi Tags for that. Works great.

Then, you'd only need to have some logic somewhere to activate the shelly, which would in turn fire the heater. Node-Red would be great at this.

I had intended to do this on my old boat, but life changed and I had to sell it. In the market now for a replacement and will be doing this exact thing on the next one.