Atwood 15K Rooftop Heat Pump Md #15028

I recently purchased a 15K Atwood Air Command Heat Pump Model 15028; it’s a ducted unit with a digital thermostat. The Original unit was a Dometic 13.5K AC. The removal of the Dometic and install of the Atwood was a breeze, the hookups are about as simple as it can get. The only problem is that it won’t work in heating mode; The AC works great, no problem. I thought it was a faulty thermostat so i purchased another, no luck, it will come on and output excellent heat for about 20 seconds when it wants to, no rhyme or reason just whenever it feels like it, most of the time it wants to run the propane furnace, the reason I purchased the heat pump was to get away from the expense of propane and the clutter of having three cube heaters on the floor. After scouring the net for troubleshooting info I've found that every other RV heat pump I've researched is wired the same as most standard residential pumps, with separate wires calling for whatever function. With this Atwood unit, OH No. It's a four wire deal that uses pulses or some******that makes no sense to me and won’t show change on a multimeter. Had I done more research as to how the controls were built I would not have bought the damn thing. The rest of the unit design appears solid. At this time it's only 48 degrees outside so there is no excuse for it not to be running. I have spent a couple of weeks fooling around with this pc of garbage. Had they simply used a traditional control board, I’d be up and running with whatever thermostat I chose instead of some space **** they probably had aboard challenger. I just don’t get it, why would you go from using a controller that’s tried and true, used in millions of systems, to some space trash. I sure would appreciate any feedback anyone could give me about their heat pumps. Especially Atwood.