[cali camping]

One thing that may cause excessive temperature fluctuations and /or excessive cycling of the heater is where the thermostat is located relative to any heater output vents. On our 2720 SD the heater vent output was only around 4 to 5 feet away from the thermostat which was located in the standard under the sink location. When the heater would kick on the heated air didn't take long to reach the thermostat no matter which way I rotated the vent and the thermostat, sensing the increased "room" temperature would shut down the heater as it should. But in fact the room hadn't heated up, only the area around the thermostat.
To remedy this problem we installed a digital thermostat with 7 day programming higher up on the bathroom wall, more in the height range you would find in a residential install. See picture. It solved the excessive cycling problem completely to our satisfaction.