A rental property has a heat pump with electric resistance auxiliary. When vacant, the heat needs to be sufficient only to prevent freezing. While the heat pump is only a couple of years old, the thermostat is a Janitrol with mercury switch that is at least 20 years old and has a minimum setting of 50 degrees.
Need your suggestions for a digital thermostat with 40 degrees minimum setting that is powered by the 24 volt control system (batteries not necessary), not-programmable, a clock function is not necessary. Preferably will light up the display when a button is pushed. Preferably would permit the user to select the differential at 1,2 or 3 degrees.
I do not know that controls the operation of the auxiliary.
If the thermostat is suddenly turned up 10 degrees, the auxiliary is actuated. I would like for that differential to be at least 2 degrees and adjustable to 3 degrees if possible.
One of the Gem Tech models has several of these features but not all of them.
Your suggestions are welcomed.