I traced a wet bilge area to overflow from the hot water tank pop-off valve. It seems that each cycle from cold to fully heated produces about 1/2 pint. This occurs from either AC power or engine water loop. So, one could pipe this directly overboard or into a nearby sump to keep the bilge dry. But I am wondering why boats do not have an expansion tank above the hot water tank? All newish houses and condos in my part of the country have them. Must be a code requirement.
Reading Calder, WM and other catalogs I find the typical schematics showing an accumulator on the cold water side but never an expansion tank for hot water. The only reference I have found for expansion tanks on a boat is in hot water heating systems such as Webasto.
The one in my house is only as large as a typical "marine" accumulator tank. Why not pick one up at home despot for cheap and put it on the boat? I'm thinking it will also keep the psi from getting too high when a tap is not opened for several hours.
comments?
Gary