In the Hurricane/Windsport 31S there is a chase (passage) for the heat, electrical and plumbing that goes from the left side of the entry door to the outside kichen. Major supply points for this chase are: top of the battery compartment into the door's hollow wall, under the shower (cross coach water lines are accessed in the heated basement compartment under the shower and behind the water heater) and under the ouside sink.. Common access to the chase is from: the false floor under the kitchen sink, the air vent under the fridge and the water heater access under the dressing table by the closet. Hollow walls are: the left side of the entry door, the wall between the shower and the dressing table and the outer bathroom wall in the hall. The cabinets above the couch have a false floor as do the ones in the kitchen. Because of the aluminum bracing in the wall only the HDMI cables run through the outside walls. There a couple exceptions where electrical wires do run vertically in the outside walls. All this is info is shown on the engineering drawings available from Thor MC CS.
In the outside kitchen, the water pipes, macerator and 1.5" waste water line are all in an compaerment heated by the propane furnace, unless you have a disconnected or blocked heater hose (those 2" silver hoses in the fresh warer compartment, the wet bay, basement compartment under the shower and in the outside kitchen (under the sink.)
If it is below freezing outside, it is best to use ONLY the propane furnace to heat the coach. Using supplemental heat in the coach can cause the tanks and water lines to freeze.