I’ve got a Freightliner with a Thermoking TriPac. I understand and use the air conditioning with no complaints. The heat either barely works or I’m not using it correctly. Here’s wjat I do:
1 press & hold the on/off knob
2 rotate A/C, Fan, Heat knob to heat
3 rotate temp knob fully clockwise into red zone
4 wait
The APU kicks on, air starts coming from vents. Many minutes later the air is barely at room temp, if that. I haven’t had real cold yet so I havent taken time to read through…