Well my Coleman is also ceiling mount.. My next suggestion is same as Doug's. if that dont' help and the thing is new consult a professional as you will need their support for warranty repair.
Of course it will work 100% with the pro in the house
OH. that's another thought. There is what LOOKS like it should be a freeze sensor BUT IT IS NOT. it's the intake air tempsensor
now with my Carrier controlled Advent air I have a freeze sensor stuck in teh coil.. but on the Coleman the sensor is supposed to hang in free air.. NOT in contact with the coils. That might be the issue.
Careful pulling the grill as when you remove the knobs there is an extension between the knob and the control shaft. Hard to find replacements (I had to fabricate one)
