Chronic A/C cycling in Newmar Dutchstar
I have been battling an A/C issue for several months and have been at the dealership now for more than three weeks. Here is a summary.
We own a Newmar Dutchstar 2009 4010 that we purchased from dealer in CT just over a year ago and have been full time since 11/2018. We have 2 Dometic Penguin heatpumps (M/N 630515.331D - 13,500 BTU R-22) with CC1 control system and aqua hot domestic water and heat. Single supply air duct front to back on MH as well as return air duct. Experiencing erratic operation of a/c. Lost communication which prevented a/c during hot spell. Replaced the CC1 control with new - no change, still very inconsistent operation. Finally got proper reset and communication established and when we approach setpoint (within 2-3 degrees) the units start short cycling (on 5-10 minutes, off 4 minutes or so). Brought to dealer and was told it needed one control board in front heatpump. This was replaced and short cycling continued. Dometic suggested several remedies. 1-New communication wires; 2-New 12 volt wiring away from other wiring; 3-RF interference from lighting. Replaced all ballasts in fluorescent lighting. Ran 12v wires from house batteries up to each heatpump on outside of coach. Ran communication wires along roof and into window to eliminate RF interference. Put each heatpump on its own CC1 controller to separate problems. Replaced control boards in each unit from another RV with same control system and age. Replaced run capacitors in both. Short cycling continues as you approach setpoint in both units. If we set the temp very low on thermostat, both units will operate continuously until they get to setpoint, whether we set temp at 67 or 74. Then the cycling begins. We (and the dealer and Dometic) are at a loss to remedy this situation - or is this operation expected with the older dometic CC1 control system?