EM heat? There is no other heating unit. What is the difference between stage two and aux? Please note that the aux gas heat cannot come on if the heat pump is running or it may hurt the heat pump due to the gas heat units location
Heating & Cooling
Answers & Comments
Stage 2 is okay as long as there is a fossil-fuel kit accessory wired in the field control wiring. EM heat would only allow gas furnace operation if the thermostat is set for EMER HT mode.......this is not ideal and not recommended. Dual-Fuel applications require a fossil fuel kit.
I'm including a link with information on one type of fossil fuel kit. It explains how it works. If you have limited HVAC service knowledge and/or experience, I recommend having an experienced service technician check your system operation in all modes to ensure proper operation for longer system life at peak operating efficiency.
http://www.ntsupply.com/files/products/ffk100operation.pdf