When shopping for on demands, we found the factory made RV models ran about $1500 and had to be professionally installed. Too rich for my blood. But being a remodeling contractor who channels Agent McGyver every once in a while, we got to thinking about the old rLP HWH from out Popup days which we had setting in the garage.
We just finished installing the unit. Its an
EccoTemp L5 It was the way we heated water for our PUP and it worked fine.
A diverter tee* was added to the cold water supply pipe heading into the factory installed 6 gallon HWH, from that tee a pipe runs to the HWH which is hung on the roof ladder at the back of the trailer. The heated water leaves the on demand heater then flows back to the incoming pipe just after the diverter tee, with the pre-heated water filling the stock hot water heater. The on demand heater attaches and disconnects from pipes run under the trailer to the rear corner, using brass quick disconnect fittings to the hoses connected to the tank. Total cost ; heater $120, pipe and valves; $146 for a total of $266 (but we already had the heater)
To keep the quick connects on the rear of the trailer clean, we installed a temporary jumper hose which stays in place when the trailer is in transit or not in use.
So far we have performed only a leak test and temp test which it passed. This weekend we are camping with a group of 15. We will be supplying the showers for all if this goes well. (they have tents)
I'll keep y'all posted
* about the diverter tee - it has a quarter turn only. In one setting cold water flows to and from the on demand. In the other setting it bypasses the on demand, flowing right to the factory HWH. If the on demand runs out of gas or has problems we can turn the valve. With nothing attached to the external pipes it doesn't matter where the diverter is set as the incoming water simply makes a longer loop around to the factory heater going through the jumper hose.