Water heater replacement, Atwood or Kuuma?

[pablosgirl]

While on the boat this week I noticed that the bilge pump was cycling and so was the pressure water pump. So the original Atwood water heater is shot.  Some online shopping shows that I can get the Kuuma 11812 from Hodges Marine for $297.05 and the Atwood marine S600 from Boat & RV Accessories for$385.09.  Both have the same dimensions with the rear heat exchanger connections.  Does anyone have any experience with either of these.  I am inclined to go with the Atwood since the original lasted this long. Does anyone have the Kuuma model and was it a drop in replacement.

[waughoo]

I have the Kuuma, but it came with the boat.  I have no knowledge of how old it is.

[scgunner]

Paul,

I'm impressed it's lasted this long my original rusted through about 20 years ago. It was a regular non-marine RV unit. I replaced it with a marine unit with a square S/S case which fit the space and worked fine until I took it out of line when I installed a flash heater.

[Ron Hill]

Paul : I found that the galvanized outside does the job. If you use Stainless (more $$) you don't gain much because they all have the same insides (NOT stainless)!!

A few thoughts

[Jeff Tancock]

Check all your fittings. I thought mine was shot but on examination it was just the plastic hot water out elbow fitting that was leaking. Had to replace with a brass fitting as that was all I could find on a remote island.
Lucky.....A $10 solution!

[Ron Hill]

Guys : I replaced the both the inlet and outlet with brass fittings.  I found that the outlet got very HOT because it transmitted the heat from inside. I changed the outlet elbow back to nylon.

A thought

[pablosgirl]

Hi Jeff ,

Thanks for the tip about the fittings.  I had already checked them. Also there was a pretty obvious stream of water flowing out between the bottom of the water heater and the plywood shelf. In addition the whole bottom of the outer case was pretty rusted. I think I got my moneys worth from it. I am now hoping for a Black Friday sale on marine water heaters. 

[Jim Hardesty]

When replacing the water heater consider adding a by pass.  Even if you don't need to winterize it may be worth the few extra bucks.
Jim
https://www.westmarine.com/camco-water-heater-bypass-winterizing-kit-329195.html?utm_source=pepperjam&utm_medium=affiliate&utm_campaign=159404&utm_content=4923727131&clickId=4923727131&cm_mmc=AF-_-Pepperjam-_-159404-_-4923727131

[pablosgirl]

I bypassed the hot water heater until I get a new one with a 1/2" nylon splice connector from WM. The bypass is a good idea but I live on the Texas gulf coast and I don't think it is worth the effort for me.  I will be replacing the hoses to the engine.

[Noah]

Two "upgrades" I did on my fresh hot water system.
1. Added a temperature mix valve, to better regulate how hot the water is coming out of the tank.

2. Re-plumbed the hot output side with PEX A tubing to both sinks, which is better suited to carry high temperature water than original vinyl fresh water hose.