has the Precisiontemp RV 500. It was installed by the previous owner. It works well, uses very little propane and is quiet. They are expensive, and probably not a cost effective way to produce hot water in an RV with one or two people. We do like the fact that it only fires off when the water is turned on.
We have a conventional water heater in the Excella. It has an on/off switch inside the trailer. First up in the morning turns it on, off after breakfast dishes. Water is usually still warm enough if we need it at lunch.
We turn it on again in the evening for dishes, showers etc., then off at bed time.
It, like the RV 500 in the Caravel
, only runs when we want hot water.
Really don't want to use propane to heat water when not needed. Besides the cost, you have to go get it, and on the Excella that means dealing with the nice tank cover as well.