Fan Coil DIY thermostat

First of all. Hello!, this is my first post. My name is German and I am from Chile

I am looking for a solution to include the option of controlling a three speed fan as an additional function of the generic thermostat.
Basically I want to control a HVAC system that has a coil for heating, a valve for cooling and a fan that has three speeds, each of them controlled by an independent switch / relay.
The most important condition is that neither the coil (heat) nor the valve (cool) could be on if the fan is not running (specially the coil, because that can lead to a fire hazard).
So far I can control both the coil and the valve using the generic thermostat, a Sonoff temp sensor (NSPanel) and 2 Sonoff switches (DUALR3). But I am missing the fan control.
I have seen such a solution for a ESP32 based thermostat & Home Assistant (fan coil thermostat with ESP32 and Home Assistant - YouTube) but can’t find the way to implement that solution directly in home assistant using a Sonoff temp sensor (the one of the NS Panel) and 5 Sonoff switches (heat, cool, fan speed 1, fan speed 2 and fan speed 3)

Best regards and thanks,


Any idea??

Hello, glaso. I’m looking for the exact same thing. Did you find any solution or idea?