I have an Entegra with the tubes under the floor....when you turn it on, you set it about 8 degrees higher than the rest of the coach...Within about 12 hours, the radiant heat will roast you out and the other zones don't even come on...I've been out to 8 degrees and between that and the basement heat we were fine...The other two zones only came on while the floor was heating in the beginning..this also radiates to the basement as well, keeping the piping protected..the coach is also well insulated so it holds more of the heat. although with this sytem there may be a cold spot but that gradually absorbs heat too...also one drawback that the rear bath since it is over the engine does not heat thru the floor.. For that, turn on that zone.