Despite my best effort to find a good installer, the installation of a new heat pump system has been a nightmare. Thankfully, with persistence, I have been able to get problems resolved. However, over the weekend, I realized that during the defrost cycle, the auxiliary heat does not kick in. I had 40 degree air coming out of the registers during the defrost cycle. Outside temperature was in the high 20s. When I put the system in emergency heat mode, I did get warm air from the registers. There must be a wiring problem. Before I call in the installer again, I would like to find out what is the correct wiring. I dont plan to change any of the wiring myself, I just would like to know what is correct so I can make sure the job is done right. Below is the information on the equipment and how they are wired: Trane Heat Pump: 4TWX5024A1000A Air Handler: 4TEE3F1B1000A Thermostat: TCONT802AS32DAA 10 KW back-up heat: WBAYHTR1410BRKR The wiring is as follows: Thermostat > Air Handler > Heat Pump Red > Red > Red Orange > Orange > Orange Blue > Blue > Blue Yellow > Yellow > Yellow Green > Green > Green (not wired just hanging loose) W1 white > W1 white The dip switches on the air handler are set as follows for Comfort-R: 1 off 2 on 3 off 4 off 5 on 6 on 7 on 8 off The green wire to the heat pump is connected at the air handler, but just hanging down and not connected to anything at the heat pump. Also, my understanding was the auxiliary heat was to go on in two stages. Is the wiring setup to do this? Any help that can be provided will be gratefully appreciated. I just want the system to run correctly. Thanks.