PILOON
Super Star Member
I have to assume it never freezes in the barn, since a "flow through" type water heater is not frost protected.
I also think that a small conventional electric heater, fitted with a time based thermostat (only HOT during the hours needed) would work perfectly for the job. Provided the "idle" temperature is warm enough, you also have freeze protection. Perhaps not needed for your application, but surely required in the midwest.... Just how much hot water is needed when doing laundry ?
As to 'IDLE' temp, we once had a 5 day power outage and I simply needed a shower and decided to shower no matter how cold it might be.
Much to my surprise as long as I did not mix any cold what came out of the tank was still very comfortable and not even chilly.
The newer foam insulated tanks really are efficient.
I venture to suggest a standard tank switched on about 1 hour B4 a washing probably would be just right.
Most newer ranks with dual elements really have a great recovery cycle.