Hot Water Heater Replacement Installation

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Hot Water Heater Replacement Installation

This is a short description of a hot waterheater replacement installation just completed on a Cape Dory 31.

The original Raritan 6 gallon hot water heater had been slow leaking for a number of years and began to leak its entire 6 gallon contents into the bilge very quickly last year. It needed to be replaced after 30 years.

First steps included consulting postings on this web board and researching on-line to select a replacement. The currently manufactured Raritan 6 gallon model may or may not have fit with some significant effort and had a high price, a Quick B3 20L seemed like it would fit based on dimensional drawings; the square configuration RV style 6 gallon would definitely fit. I would have liked to go for a higher quality of engineering and resulting longevity, but based on how the boat is used, that it receives diligent winterization service, that I routinely service and replace the cooling system pencil zinc and the significant price difference, the RV style, with nominal marine service improvements was the choice. Now that I know the replacement drill, even if this one fails after just a few years, the lower price is still advantageous.

A West Marine Model # 13915103 Mfg # 11811W 6 gallon was chosen with engine heat exchanger and 120v shore current heating. It is a re-branded Kuuma RV style waterheater. It had the advantage of being on the local West Marine shelf so it could be installed immediately. The price was US$269.

The installation process included a visual inspection of the old unit, plumbing, wiring. We also determined that despite the leak, the plywood platform that the waterheater sits on appeared sound and un-rotted. We could not tell which line to the old unit was the domestic water line-in and which was line-out, important for reconnecting to new unit. I did not think at the time of simply turning on the water pump and noting the hose that spouted water! None-the-less we marked one of the lines just to be able to tell the difference between the two.

The expansion tank for the engine cooling system had to be unbolted, it was hung from a bracket off of the rear of the cockpit locker. The engine coolant, domestic water hoses and the wiring were then disconnected from the old unit. As we disconnected the old unit, we made sure to identify the hot, ground and common electrical lines for the AC heater unit. The electrical connections were well marked on the Raritan.

The physical removal of the old unit was relatively easy. Three wood screws on a mounting bracket secured the unit. Two were accessible and easy to remove the third was apparently put in before the deck was lowered onto the hull. We were about to simply pry the screw up and out of the plywood when a bit of English was applied to the unit, the rusty bracket snapped right off, the unit came loose, and significantly, it came through the cockpit locker opening with barely a scratch on the fascia of the locker. It was a total rust bucket, surprising it kept working at all over the past number of years.

The new water heater also slid right through the locker opening and fit perfectly on the existing shelf. We checked to be sure it did not come in contact with the back of the shore power plug located on the wall of the cockpit. In fact it was below it. We could not reach the rear 3 hole mounting bracket but did secure the front bracket to the plywood with 3 hefty screws An angle bracket was screwed into the plywood about two thirds back on the outboard side of the unit to keep it from shifting outboard in rough conditions, the inboard side rests securely against the cockpit wall.

4 threaded male to hose barb couplers were used to transition from the old grey plastic domestic water hoses to current transparent domestic water hose, then to the domestic hook-ups on the new water heater. Be sure to get the line-in supply on the lower of the two connection sockets. The engine cooling lines fit right on the male hose barbs on the unit. The line from the engine should go directly to the heater, the line to the header tank on the other connection. It does not matter which although the instructions were not very clear on this point.

We had to relocate the engine expansion tank. It would not fit back at the rear of the locker because of the length of the new waterheater. We drilled the teak fascia for the mounting bracket through bolts and installed it on the rearmost portion of the inboard fascia. That is where the existing hoses worked best and maintained accessibility for occasional top offs. The electrical wiring was well marked on the new waterheater,we used crimped butt connectors with a layers of heat shrink insulation over the connection.

We recharged the engine coolant system with antifreeze, some was lost when the hoses were disconnected. We started the pump to fill the tank, started the engine and bleed the air out of the system in increments, running, then stopping to bleed the system at the engine bleed pepcock, until coolant/antifreeze flowed without air or bubbles.

That’s it so far, the water is hot, hot, hot, heats up quickly with both engine heat and AC

Finally, note I had the skinny son of a friend of mine who was volunteered for the in-locker portion of this work, very helpful. Now all of the connections and the drain valve etc are on the front of the heater, accessible leaning over the edge of the cockpit. If this one fails early, pulling it out for another replacement does not be nearly as daunting nor difficult.