Nice! I have one of the single stage Fahrenheit ones. It does indeed look like this one is dual stage according to the schematic. Fortunately for me, I have no need for heat. I live in a hot climate, so heat is plentiful. The single stage works fine for my needs. I believe I have read that it's possible to flash the Celsius dual stage ones over to Fahrenheit, but I'm not honestly sure if that is true or not.