Having a HVAC tech replace a Honeywell digital thermostat with a Honeywell RTH6580wifi thermostat. The current one runs a 30 year old Weil-Mclane boiler in the lower level (forced hot water baseboard heat) and a 2 year old A/C unit in our attic. The heat is three zone, the A/C is one zone, this thermostat controls one heat zone and the A/C. On the current thermostat the G, W, Y, R, and Rc terminals are being used and it works fine. We are in Michigan so the A/C is shut off at the breaker box for the winter and is not on the whole house generator, the heat is on the generator. Of course, there is no C wire from the Weil-Mclane so the technician is using a Fast-Stat Common Maker Thermostat Wire to try and make it work.

He is now telling me, and his phone call to Honeywell seemed to confirm, that it is not possible to make both the heat and A/C work on the one wifi thermostat, he will have to leave the old thermostat for the A/C and install the new wifi thermostat for the heat. I want the wifi for the heat so we can check the house temperature while we are away. Has anyone come across this situation before, and if so, is there a better solution than 2 thermostats?