I have a heat pump w/o heat coil and would like to use my boiler & hydronic baseboard heat as the primary heatsource under 35 degrees. I purchased a Honeywell TH8320U thermostat and a wired outdoor sensor to control the HP lockout. The boiler is controlled by a Taco ZVC 405 Zone Controller.
I currently use 2 thermostats to control the heat pump and 1 boiler zone.
My main question is how do I handle the 2 seperate heat transformers and connection to the thermostat?
Can I use the boiler 24v for the R terminal and the HP 24v for the Rc terminal and connect Aux to the zone controller?