Does Water Heater Work Off 12V?

[Mark Sutherland]

I'm a relatively new owner of a 2006 model 350, and have always used the water heater after the engine was running, or when on shore power. My question is, will the water heater run off of 12 volt DC, or only AC via shore power on an inverter? Thanks.

[leigh weiss]

Mark,
My water heater has a heat exchanger from the engine coolant and a 120 volt input for heating on shore power like yours.
I think the Power requirements for the 120 volt heater element is over 1000 watts. Your 12 volt system (battery/alternator) will not be ample enough to provide hot water at this power level if you had a 12 volt heating element installed.

[wolfe10]

Correct.

The water heater is ONLY motor-aid and 120 VAC. You will have a breaker for it on your 120 VAC panel.

[nybor]

Hi. Leigh and Bret are correct. Mine is also a 2006 model. I do have an inverter, but don't see any advantage trying to hook the water heater up to it, since you would have to run the engine or the batteries would die.

What I did do - I have two Yamaha 2000 W inverter generators (aka like the Hondas). I have a connector that runs them in parallel, so I can plug them into the shore power outlet and run the a/c. Funny, since it is always the starting current that is the limiting factor, once I get the a/c running, I can shut down one of the gens an it works fine! (I know, I have a super capacitor that I should try, but....scared)

Anyway, you could buy a small Honda 1000 generator and a converter plug hooked up to the 120 VAC boat plug. That way, you could use "shore power" to heat the water and to charge the batteries - of course not at the same time. Since the heater is pure resistive (no motor start induction draw), the little generator should work. One of my Yamahas 2000 works fine and I can do both, water heater and charger.

dave

[sargentef]

Mark,
My 2 cents... the hot H2O element in our hot water heater is a 1500 watt element. We purchased a "Honda clone" 2000 watt inverter generator. The generator states that it will put out 1600 watt continually and it does power our hot water heater, it takes about 45 mins for really hot water, 20 mins for luke warm.



We also have a Honda 1000 watt generator that will run the battery charger very well along with some lights and the laptop charger and vhf hand held charger. It will not run the AC, micro wave, hot water heater!

The 2000 watt gen doesn't run the AC! Yes, there is a super start capacitor that will lower the start up wattage but we have a friend who installed one and he feels that it damaged his AC unit. The 2000 watt gen will not run the hot water heater and micro wave at the same time. It will not run the hot water heater and batt charger at the same time.

Erik
"Seawing" hull# 309 2005

[Mark Sutherland]

How long do I need to run my engine to heat up the water in my hot water heater for a shower?

[sargentef]

45-60 mins for a "Hot" shower.

[agoss60]

Just a quick note, I installed a Cruisair 16000btu air con with optional soft start module. This module ramps up the air con slowly so the current draw stays manageable for a 2000 watt generator. I found all other high current draw items such as water heater and in my case 40 amp battery charger have to be off for this to work.

Cheers
Alun
S.V. Alarah
2004 Catalina 350