This topic has been discussed ad nauseum, but I cannot resist piping up again. I have a Girard tankless and finally got it to work (sort of) for camping with city water only (forget hot water if dry camping). I bought a water pressure regulator set at about 50, set water temperature at 100 and run water in the shower (or elsewhere) for a long long time until I get consistent warm (not hot then warm then hot then warm …). I finally have warm water to shower and my wife will now go with me if we do not dry camp.