For perspective, Fred, on ours the water tank is right next to the HydoHot and keeps from freezing by the proximity. The pump, ice maker filter, and main associated water lines and shut offs are enclosed in a plastic box high on the wall of the waste tank bay that adjoins the main storage bay, curbside. Access to the pump is via removal of a carpeted panel from the storage bay side. I note other similar access panels in there but have never sought what was behind them; likely for getting to important chassis or utility components.
The heat exchanger is on the waste tank bay ceiling. A thermosensor probe that may be the exchanger’s is bay-front center with other devices in a protective wood loop. The bay exchanger has no ductwork, only hydronic tubing similar to the exchangers inside the coach, and uses an independent thermostat preset to come on at around 40 as long as the HydroHot is on. The water utilities bay with the multicircuit water valve manifold is at the opposite end (street side of the waste tank bay), and is protected by the exchanger’s proximal heat. Though, unlike yours, our exchanger points toward the bay door, there appears to be enough convective action, over the top between the rails perhaps, to warm the storage bay.
Joel
