D-tub Heater

The heater for both the tub and shower is a Webasto DBW2020, an 80,000 BTU diesel-fired water heater, which served a school bus in a previous life.  Technically a coolant heater, the water from the heater runs through a heat exchanger to transfer heat to the tub water, keeping the chlorinated water out of the heater.  This is mostly to keep the heater in good condition rather than an attempt at avoiding tub contamination: the heater is made of mild steel, which will corrode if left in contact with tub water over a period of years.

The heat exchanger is stainless steel, and had a former life as a water bath cooler, also acquired surplus of course.  Weighing in at about 80 lbs, and costing thousands new, it it was one of my best surplus finds for the project at $30.

At the maximum fuel consumption of 0.8 gallons/hour, the 26 gallon truck fuel tank should last for 32 hours of usage, which should be enough for a long weekend of usage.