Re: Near constant hot water without a generator - Here is how i did it.

Ryan Meador

There's nothing special about "AC" vs "DC" for these heater elements, but the voltage does matter, and in common boating usage these current types imply a voltage as well.  The element is just a resistor, so to achieve the desired number of watts, the resistance is sized for a specific voltage.  If you run a 240V element at 24V, you'll get 1/10th the rated output (and vice versa will likely explode).  The other electronics involved (like the thermostat) may actually care about AC vs DC and the voltage; I'm not sure.

Some marine water heaters have two ports so you can have both AC and DC elements at the same time.  I've heard using a DC water heater element as a wind generator's dump load works well.

Ryan and Kelly
SM 233 Iteration
Boston, MA, USA

On Mon, May 18, 2020 at 3:25 AM Matt Salatino via <> wrote:
Our water heater is an Isotherm.
I haven’t looked at the element nut size.


On May 18, 2020, at 7:36 AM, Eric Meury <ericmeury@...> wrote:

hey matt. 

im not 100% sure if there is a difference but i do know that my AC element way to many watts going out.  This is the unit i purchased.

it will work for 12 or 24 volt.  I think if you goole the type of water heater you have you can find out the size of the element.   You will most likely need the professional tool to remove the water heater element.  The cheap home ones will simply not do the job.  at least on my tank that was the case.  ...What brand of water heater do you have?

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