I'm trying to install a Nest Thermostat E on my old dual-fuel (propane) heat pump. I'm confused about the W wire. I understand that it's used by the thermostat to call for auxiliary heat (if the outside temperature is too low or the set-point is much higher than the current indoor temperature) or for emergency heat (explicitly by the user).
So I should connect it to the W terminal on the indoor furnace/air-handler unit.
But what about the W lead to the heat pump compressor ? My understanding is that it is an output signal from the compressor, indicating that it has gone into a defrost cycle. So do I just connect it to the W terminal on both the thermostat and the furnace/air-handler, so that all three W terminals are connected together ? Won't there be an electrical conflict between the thermostat and the compressor, since both are output signals ?
