Return vent below shower - hot air

wborst wrote:
On our Newmar Mountain Aire, that vent allows warm air into the wet bay to prevent freezing. In the wet bay is a switch marked HEAT. When this switch is on, and the outside temperature falls below 40* and the furnace is enabled, a fan comes on that pulls warm air through this vent into the wet bay.

Sorry, That is not where Newmar PULLS the furnace air for the Wet Bay. There is a 4 inch flex duct connected to the Metal Floor Furnace Plenum and at the exit of that round hose inside is a 12 volt Fan and motor. If you look inside the storage bay and look UP you will see this tube. Doug (I Serviced and We sold Newmars from 1994 till 2008)

wborst wrote:
On our Newmar Mountain Aire, that vent allows warm air into the wet bay to prevent freezing. In the wet bay is a switch marked HEAT. When this switch is on, and the outside temperature falls below 40* and the furnace is enabled, a fan comes on that pulls warm air through this vent into the wet bay.

Our Mountain Aire is the same except when you turn on the switch the fan in the basement suck air from a front floor heater vent and the vent under the shower warm air comes out to do as you said , keep things from freezing in the basement. If you turn that switch on in the summer then you can suck cold air out of the coach and cool down the basement and the warm/cool air will come out of that vent under the shower.

On our Newmar Mountain Aire, that vent allows warm air into the wet bay to prevent freezing. In the wet bay is a switch marked HEAT. When this switch is on, and the outside temperature falls below 40* and the furnace is enabled, a fan comes on that pulls warm air through this vent into the wet bay.

MountainAir05 wrote:
The vent is for the heater, but it could be drawing air from the AC return and that air is hot from the basement. In other words its sucking air from the basement.

2000 Bounder would not have AIR or AC return or ducts in the floor. The Roof AC's just recycle the existing air inside the RV. BUT, when you have various holes in the floor that go into the basement, it will draw up that warmer air. You need to seal the water line and P trap assbly cut outs under the shower with spray foam or just stuff fiberglass insulation in the access hole. Usually, that "vent" is an access cover for getting to the Shower drain plumbing. Doug

The vent is for the heater, but it could be drawing air from the AC return and that air is hot from the basement. In other words its sucking air from the basement.