RVP has that 5 degree separation point. WHAT the system does is this. Once the system reaches your set point, the HP should be able to maintain that set temp without having a 5 degree or more drop. IF the outside temp and conditions are such that the inside of the RV drops more than that 5 degrees or ANYTHING that causes a more than 5 degree drop and this means even if the HP is on but the inside temp cannot be raised before the inside temp goes past that 5 degree threshold, the Furnace (or Aqua hot) will assist the HP. If the conditions are such that this happens so many times, the system determines that the HP is futile and the furnace (or Aqua hot) needs to be the primary heater, until those conditions change. In almost ALL circumstances, above 35 degrees, that strike rule will never happen. Doug
PS, Kudo's, somebody ACTUALLY read the instruction manual:B
