Used heat pumps and furnace for the first time this past weekend. Just want to report my observations
Zone 1 Gas: furnace comes on
Zone 1 Electric: furnace and heat pump both come on, heat pump cool air, thermostat stuck at 60, furnace continues to blow warm air without turning off*
Zone 2 Electric: heat pump comes on, warm air
Zone 3 Gas: furnace comes on
Zone 3 Electric: furnace and heat pump both come on, later only heat pump comes on, warm air
*my guess is that the Zone 1 furnace blows warm air into Zone 2, but its thermostat is located in Zone 1. Zone 1 is left cold, heat pump not strong enough to warm Zone 1, thus thermostat stuck at 60 degrees.