[Silvertwinkie]

Well, I think that there is a check valve which might not be working correctly and or there is a leak some place. Ours also cycles when not in use, but prob only 1 time every few hours if not longer....every 2-3 seconds though clearly is far too much. Have you checked the water heater and made sure that everything is properly closed? Does it cycle this way with the water heater by-pass on and off? Also, you can access the pump, see the tank and check valve from those little square doors under the streetside pantry and closet doors. I'd open those doors up (they are on hinges too, just no handles) and shine some light in there to see what's going on...you might see the issue right out of the gate since outside of the water lines around the coach, the main action happens right in that area.

Any way you look at it, I would think it's a warranty repair if it's still under warranty.