View Single Post
Old 02-12-2014, 05:04 AM   #11
boatpoker
Guru
 
City: Here
Join Date: Sep 2012
Posts: 2,940
Regardless of which water heater you install it will last for many more years if installed properly. Less than 10% of the units I see are installed correctly.

Most of the conventional marine units are aluminum tanks wrapped in fiberglass batting, inside a metal box. If you mount this box (as most do) directly on a deck, any drips condensation etc. will get trapped under the box where the fiberglass will wick it up. Holding moist fiberglass against the aluminum (or stainless steel) tank will greatly speed up corrosion. The tank should be mounted on non-absorbent cleats with about 1/2" airspace underneath to promote air flow . Running hoses from the pressure relief valve and the drain tap to the bilge will also help as these two items leak often.

Using a domestic unit is certainly cheaper but you will get no hot water when off the dock unless you run your generator. The same installation tips apply to the domestic units.

We lived aboard for 16yrs with a 6 gallon unit and never had a shortage of hot water as with such a small unit and the same wattage as larger units, the water heated almost as fast as we could use.
boatpoker is offline   Reply With Quote