ESPHome Based Line Voltage (Baseboard) Thermostat

I was disappointed in the lack of affordable, line voltage, smart thermostats so I adapted a smart switch into one.

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A while back, I wanted to add smart thermostats to my apartment. However, I was surprised by the lack of inexpensive, line voltage (or baseboard) smart thermostats. Originally I planned to do it all DIY, but I realized there's plenty of cheap, smart wall switches out there, and a line voltage thermostat is just a wall switch with a temperature sensor and some type of UI. Plus, I figured a converted wall switch is probably a bit safer. So I decided to make some. At the time, most smart switches used an ESP8266 so I designed a thermostat that could take advantage of the microcontroller that came with the switch. I've since moved to a house with central heat but has a baseboard heater in the bathroom. I wanted to be able to run the heater on a timer for showers in the winter so I redesigned the thermostat to use a ESP32 for the increased I/O to add buttons instead of the rotary encoder.

Full instructions, CAD, and ESPHome YAML files are over on Github


ESPHome YAML configuration for the 6-button version.

yaml - 6.42 kB - 03/23/2024 at 23:48



STEP file for button version

stp - 144.13 kB - 03/23/2024 at 23:50



ESPHome YAML configuration for the rotary encoder version

yaml - 4.68 kB - 03/23/2024 at 23:49



STEP file for rotary encoder version

stp - 173.67 kB - 03/23/2024 at 23:49


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Elliott Olson wrote 03/27/2024 at 19:47 point

Does it use NV memory to remember the settings? Our off-peak electric heat can be off for hours at a time, meaning the t-stat (in series, of course) has no power as well.

  Are you sure? yes | no

Murphy's Law wrote 03/27/2024 at 20:07 point

Anything set in the YAML file it will always remember (your default preset).  Set point changes should be pulled from memory on restart but I just tested it and that only seems to be working on the ESP32, not the ES8266.

  Are you sure? yes | no

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