I have a 2012 Fleetwood Expedition. It is equipped with 2 Coleman Mach Units. They are actually made by Airxcel. The rear unit is a Heat pump and the front unit is a straight air conditioner. One thermostat controls both units and also controls cooling and heating. The thermostat is also an Airxcel product. Each unit is connected to a control board called the upper control board. This board is optioned at the time of installation to designate the Zone of the unit and whether or not the unit is a heat pump or non-heat pump.
When all is well and optioned properly the zone with the heat pump when calling for heat will run the heat pump before running the gas furnace. if the heat pump does not satisfy the demand then the gas furnace is activated.
Since I have owned the Expedition it has never run the heat pump during the heat cycle. I have reprogrammed the thermostat telling it that zone 2 is a heat pump and it never runs the heat pump. I'm thinking the control board for the zone 2 unit is optioned for as non-heat pump. The installation directions which are part of the thermostat information call for a control box to be mounted in the return air plenum and the control board is installed in that box. I have opened each unit and opened the plenum cover and there is no control box visible.
So the 64 thousand dollar question is WHERE's the UPPER CONTROL BOARD LOCATED? I guess I got a little long winded here but that's me. I'd appreciate any help.