AKat777, you are not far off. I am referring to a Boiler with a hydronic heating system using a combination of radiant floor heat (pex tubing in the floor) and some compact fan forced wall radiators (much smaller than a baseboard). This system will more than likely be diesel fired, with an electric element for when i happen to have shore power. big advantage is it can also be heated by the engine coolant while driving, and it provides an almost endless supply of hot water for showers etc. very quiet and energy efficient system, will be supplemented with a heat pump unit for air conditioning and extra heat if it gets really cold. If installed at the time the coach is built it is simple to install. big downfall is it can be expensive, especially the ones sold for the RV world.