Water heater replacement? CD 31

[jen1722terry]

Hello,

Has anyone tried to repair or replace the Raritan 6-gallon water heater on their boat? Ours is leaking badly at the bottom, where the blue bottom meets the white side.

Thanks

Jenn and Terry

[Steve Laume]

The water heater was a mess and out of Raven when I bought her.

I picked up an Isotemp 4 Gal Slim Line unit and mounted it cross wise, under the cockpit sole, behind the engine. This puts it out of the way and keeps the weight lower and more centered in the boat. It also keeps it in a warmer area rather than in the cockpit locker. I glassed in a shelf and squeezed the thing in. It should fit fine in a CD-31. I gave up 2 Gal of hot water but we are very conservative with water use and I have never missed the extra 2 Gal. The Isotemp unit has a 316 stainless tank and some excellent insulation. It is foam instead of fiberglass. It heats up fast and will stay hot for a full 24 hours.

It looks like the 5.3 Gal unit is the same price but the extra 5" in length would not fit in my boat in that location.

By moving the thing out of the cockpit locker, I was able to move my batteries forward a bit and free up some stowage space, Steve.

[Jim Walsh]

I installed the same unit Steve mentions in my CD31. I chose it primarily because it fit through the opening for the cockpit locker. I also find four gallons more than sufficient for a hot shower. It does heat reasonably fast when running the engine and stays warm for a long time as Steve observed. Removing the old heater wasn't as bad as I thought it might be. I was prepared with a Sawzall but just used a 34 oz. ball peen hammer and latent aggression
After the old unit was removed I used Interlux Bilgekote to paint the area prior to installing the new unit. I found the old shelf to be in fine shape and bolted the new unit in to ensure it stays put.

[jen1722terry]

Having just finished the installation of the 4-gallon Isotemp slim water heater, some thoughts and observations:

Getting the old Raritan heater out wasn't too bad, though I had to disconnect the two nearby waste hoses (vented loop and pump-out) and remove the fill tank for the engine coolant. It took a few days, as I can only work in that locker so long each days.

The new unit mounts horizontally, while the old one was vertical. On our 31, the existing glassed-in plywood mounting shelf is long enough for the 4 mounting feet of the Isotemp, but the unit protrudes into the locker space. This required moving the existing engine coolant fill tank and it's mounting bracket forward about 6 inches. We ended up screwing a pressure-treated block onto the inside of the teak lip of the locker. A bit of a chore that entailed some head-scratching but not too hard.

Connecting the existing 3/4" I.D. coolant hoses to the heater was a bit of a struggle, as the existing waste hoses are nearby, large and stiff. The new water heater hoses (5 of them) had to weave around these waste hoses a bit. Also, - finding the proper connectors up here in Nova Scotia to fit new hoses to the old coolant tank was not possible. I ended up sliding the hose over the existing 3/4" nipples on the coolant tank and coupling 3/4" nipples to the new heater and sliding the coolant hoses over them, not an easy job with arthritic hands and the tight confines of the locker. It's done, but I can't pressure test it until spring. Over the winter, when we return to our US home, we'll see if we can track down better fittings..

The new Istoemp heater is NOT hard-wired to the AC power circuit like the old Raritan unit was. Rather, it comes with an installed standard cord with 3-prong plug. So I disconnected the 3 wires from the old heater, extended them with marine-grade fittings/tinned wires and heat-shrink seals, and wired them into a 15-amp GFCI plug in a exterior grade, weather-resistant box. I screwed the box to a small board I attached to the hull with Marine-tex near the water heater. NOTE: the Isotemp manual recommends unplugging the heater when the boat is not attended, an easy thing to do, as the outlet box can be reached from the cockpit thru the locker. We plan to leave the heater unplugged and the GFCI off, as we only rarely hook up to dockside power anyway and when we do, we use the marina shower and don't really need the electrically-heated hot water. The new heater reportedly keeps water hot overnight and if we need to re-heat it, we'll start the engine.

After studying the Isotemp website, we noticed that the 4-gallon version came in two styles: one with a stainless tank and stainless shell; the other with a stainless tank and plastic shell. Both have the same amount of insulation and the same warranty, but the one with the plastic shell is a few hundred $ cheaper and a bit lighter. Note also that the 6-gallon version costs the same as the 4-gallon, but it is longer and may take up precious space.

Tune in in June for the update on how the new heater works. And many thanks to Jim Walsh and Steve Laume for sharing their experiences with the Isotemp water heaters.

Jenn and Terry

[Texasprinter]

Hello,

Has anyone tried to repair or replace the Raritan 6-gallon water heater on their boat? Ours is leaking badly at the bottom, where the blue bottom meets the white side.

Thanks

Jenn and Terry

[Russell]

18 amps? Ouch. Obviously it only works in the slip, but at 18 amps, did you have to install a dedicated 30amp plug for it it? Or switch to a 50 amp plug? I guess a single 30amp plug might work if you have very few 110 loads on your boat. Maybe since its on demand you can just turn everything off before you switch it on?