Need a new water heater - how’s Kuuma?

b_arrington

b_arrington

Well-Known Member
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Feb 21, 2007
3,481
Setauket, NY
Boat Info
Back Cove 37
AB Ventus 9VL
Engines
Cummins QSC 8.3 600
I’m working on a ‘98 270 DA that needs a new water heater. Lowest cost one seems to be a Kuuma. Are they decent units?

It looks to be almost a drop in replacement for the existing 6 gallon Atwood heater.

For fun here are some pics of the unit that needs to be replaced - it’s kinda melting.

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I have the same 6-gal Attwood and also looking at the Kuumas. No experience with them, but they claim:

Kuuma Water Heaters are constructed entirely of marine-quality aluminum to help prevent galvanic corrosion. All water heaters feature an aluminum heat exchanger and a TIG welded interior tank.

Reviews are mostly positive -- the neagatives I've seen are about leaking fittings.

They also sell an anode to replace the drain plug :cool:
 
Just replaced my original 6gal Attwood with the Kuuma unit. It arrived undamaged in the box, with all the fittings. Since the original plumbing was from 2000, I installed a new tempering valve in the hot water outlet side. In my boat, I did have to do some very minor plumbing changes and for that I used new push-lock fittings.
I dont use Teflon tape in the screw in tank fittings, I use the Teflon paste which i think is better.

Now I have full flow hot water, no leaks. Good unit
 
I installed a Kuuma in replacement of my original in my 2001 280DA. Very close match in all aspects. The mounting was just a little different. I recall the pop off hose fitting was a different size, but that was a quick trip to the hardware store - no biggie.
Read your instructions, if you get the Kuuma. If you boat in saltwater and have a raw-water cooling system on your engine, the instructions will tell you not to run the engine heated water through the water heater core. They may all be like that, but I know this one is.
 
DWABoat said:
I installed a Kuuma in replacement of my original in my 2001 280DA. Very close match in all aspects. The mounting was just a little different. I recall the pop off hose fitting was a different size, but that was a quick trip to the hardware store - no biggie.
Read your instructions, if you get the Kuuma. If you boat in saltwater and have a raw-water cooling system on your engine, the instructions will tell you not to run the engine heated water through the water heater core. They may all be like that, but I know this one is.
Click to expand...

If they have aluminum tanks I would guess they would suffer corrosion and fail much like Mercruiser's aluminum manifolds did when used in salt water.

-Kevin
 
We have had 2 Kuuma heaters. First one did rot on the bottom and leaked after about 5 years. We replaced with another one, but this time mounted it on short blocks so air can circulate under it. No problems yet, but going on 5 years now. Make sure you get the zinc installed, they said that will help.
 
KevinC said:
If they have aluminum tanks I would guess they would suffer corrosion and fail much like Mercruiser's aluminum manifolds did when used in salt water.

-Kevin
Click to expand...
That’s what I was thinking. This boat is raw water cooled in salt water. The existing tank has heat exchanger fittings but they are not used.

It’s kinda a shame because I used the heat exchanger function a lot on my 270 AJ with closed cooling. The tank would heat up enough on the ride to our day to have a warm water rinse after swimming. Also, when anchored out at night l a few minutes with the engine on gave enough hot water for a decent shower - I would put the transmission in neutral and rev the engine a bit to keep the water hotter.
 
bahamabreisus said:
We have had 2 Kuuma heaters. First one did rot on the bottom and leaked after about 5 years. We replaced with another one, but this time mounted it on short blocks so air can circulate under it. No problems yet, but going on 5 years now. Make sure you get the zinc installed, they said that will help.
Click to expand...
Good call on the blocks. I have some scrap Starboard that should work.
 
I swapped out an Atwood for a Kuumu last winter. It was a rather straightforward project. I did not block mine as others have suggested. Though I'm also in fresh water...

Get yourself some sharkbites for the threaded connections. There's an 83% probability the plastic OEM fittings will break when you take them off :)

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love ours too, works as advertised. I had to drill the rivets out to get it into place on our 410 and reassemble once in the boat (with machine screws)

The alternative was to take the port exhaust riser off and at the time I thought that was a bigger job than it is. Go figure a month later I needed to replace the turbo so I had it off anyway.

I mention that because it looks likethe 370 might also be a tight fit and the cover is not removable like the attwood is
 
Phil S said:
I think you just want to show off your immaculate bilge :D
Click to expand...
I did love that boat and showing off that bilge :)
But seriously, since Brad was talking about the same boat I looked for a picture that would show the top mounted wood with the water pump etc. and this was the only pic close.
 
Purchased the Kuuma as well for my 2003 240 DA. I plan on using the raw water heating in salt water. Will it last for a couple seasons?
 
Erick said:
Purchased the Kuuma as well for my 2003 240 DA. I plan on using the raw water heating in salt water. Will it last for a couple seasons?
Click to expand...

Aluminum in salt water can be problematic as the Aluminum will act like an anode and the corrosion will eat through it.

-Kevin
 
If you need to winterize your water heater, add the camco bypass kit. I redid my WH in the last boat (1994 300). We replaced all the plumbing with 1/2 pex too.
 
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