I have a trane XL14c Dual Fuel unit with 3 stage heat (heat pump, low fire gas, high fire gas). It is wired to a Honeywell HZ432 zone panel (2 zones). I notice that the W1 wire is connected from the unit to the panel, but there is no connection at W2. Shouldn't W2 be connected to enable the 3rd stage of heat (high fire gas)?
I also noticed that the wiring from the thermostat EIM (VisionPro IAQ) to the zone panel also has only W1 but no W2 wire. So it appears to me that the thermostat, which is capable of controlling 3 stages of heat, will not be able to control stage 3 heat, correct?
The manual for the Trane unit says that if there is a jumper frrom W1 to W2 on the unit, then stage 2 heat will run for 10 minutes and then kick up to stage 3 heat automatically. I checked on the unit, and there is no jumper. So it appears that neither the unit nor the tstats are wires to enable stage 3 heat. Am I correct?
Also, in the unit, I notice that the W1 and the W3 wires are both connected to the W1 wire that run to the zone panel. In other words, the W1 wire connected to the panel from the unit is actually the W1 and W3 spliced together. Why would that be? What does W3 do?
My goal is to
a) Ensure that SOMETHING will enable and control 3rd stage heat, and
b) Preferrably wire things so that the tstat and not the unit controls the heat stages.
Any help is appreciated.