new water heater

[CJB220]

The water heater on my 2005 36 has "given up the ghost" and is leaking. It is a Force 10 Model 405001, 5 gallon, with engine heat exchanger and side mounting tabs. I have been looking at the Kuuma #11800 (5 gallon) as a replacement. Does any one know if this is the "closest" replacement unit or does some one have a different recommendation. Also, any ideas on how to conserve engine coolant while swopping the units? I was going to plug the coolant line as they are hard wall hose, so as to not loose coolant. Is this necessary? Finally, what are the suggestions using the temperature compensation valve (thermostat available on SBO) versus a mixing valve? Thanks - Chris

 

[sailcapt340]

On my 2000 Hunter 340, it came with a Seaward S600 heater, I have replaced it twice and always with the same model (6 gallon). This was due to the very limited access space it is located in. I have about 3/8” (maybe less) of space from the top of the unit to the under side of the settee seat. All the other water heaters available are just too tall for my use.
Check your heights and widths in your location before buying.
I didn’t get a whole lot of coolant loss when I disconnected the lines from the back of my heater. Maybe a cup or so. And that’s easily replaced at the engine. I don’t think you really need to cap the ends as you say and it may not be possible anyway once you loosen them from the heater.
Just have a good supply of absorbent towels or padding under them. Engine antifreeze is a mess to try to clean up.
Here are few photos of my replacement for you to see the amount of fluid and location as a reference.
I don’t have a mixing valve, probably should, we’re just very careful of the water temperature. It is hot!
Hope this helps you out.

 

[CJB220]

Sailcapt340 - thanks for your input. What a great idea to use a ziplock / plastic bag and towels to catch the coolant!

Thanks Again. Chris

 

[Stu Jackson]

You could also disconnect the hoses at the engine end to avoid draining the coolant in the engine too depending on your engine / hose layout. My hoses connect above the coolant tank on the engine. This limits the loss to the fluid in the hoses only.

Seaward and Kuuma are almost identical in outside dimensions. Kuuma, Seaward and Isotherm are Chevy, Buick, Cadillacs.

I made two short hose connections (extenders) at the back of the heater, double clamped, so that it was easier for me to connect to the engine hoses, rather than trying to pretzel myself into making those clamps at the back end of the heater. Location, location, location...

Our 40 years of experience with Catalina 34 boats gives Seaward 12-16 years of use, Kuuma maybe 2-4 years less. isotherms seem to last forever, but usually entail spacial restraints 'cuz they're a different shape. Too bad; I'll bet many of us would love to have them but they just can't find a place.

 

[CJB220]

Stu - thanks for the ideas. I have disconnected the hoses at the engine end when flushing and replacing the coolant, which I did a year or so ago choosing Shell Rotella ELC for the refill. I made a mess and developed an airlock in the water heater! Thanks for your input. Chris

 

[Stu Jackson]

and developed an airlock in the water heater! Thanks for your input.

You're welcome.
Next time, burp your heater hose, just remove one end from the engine and fill it up with a funnel.

 

[BigEasy]

Stu - thanks for the ideas. I have disconnected the hoses at the engine end when flushing and replacing the coolant. I made a mess and developed an airlock in the water heater!

Next time, after you disconnect hose, attach the hose using a barbed fitting to a hand pump, remove heat exchanger cap, & pump old fluid into an empty 5 gallon gas container. Flush & pump flush water into same container. Mix new coolant & pump from new coolant container into system by way of same heater hose. When coolant flows to top of heat exchanger filler, the system is filled. Minimizes mess & eliminates problem of air locks.