OK --time2roll's advice is always pretty darn good, so let's rethink this. It looks like Gordon's ultra quiet brushless pump might be an option -- I am not sure how that would work without triggering my noisy main pump? Or Gordon, did you completely replace your stock pump with the brushless one??
I know there has to be a solution here -- there must be a way to quietly cycle hot water through the fresh water tank intermittently, so as to keep the lines open, using propane (a much better source of heat than electrical resistance).
The "energy density," portability, and availability of propane is so much greater than that in an ordinary battery. Someday, lithium/air batteries will approach the density of hydrocarbons, but we are not there yet.
