I'm new to houseboating, (July 05) and (suprise) I have a ton of questions. Thanks ahead of time for all of you with houseboating knowledge making a board like this possible!

My Harbor Master has a 19 gallon 120v water heater in the engine compartment. It looks to be from a Home Improvement store. It's definitely a DIY installation. It works, but I want to replace it with whatever should be there. 4 questions.......

1. Does anyone know what was likely to have come on it originally? This one takes up too much room where it is and just plain looks wrong.

2. Does anyone have any recomendations on what I should replace it with?

3. What details should I make sure I include in the new installation to do it correctly? (type of line, connectors, wiring, etc.)

4. Should the new unit be relocated to the mechanical room with the holding tank?

I want this to be safe and reliable, I appreciate any advice you might have. Thanks again!

Matt

You may not have to replace it. But if the boat has gas engines, the
water needs to be removed from the engine room ASAP...electrical
connections on household appliances are not spark protected...which
means any gas fumes and BOOM. It works, so if you can move it and
install it correctly (assuming you're right that
it isn't) in a location that doesn't expose it to gas fumes, there's no
reason to replace it.



It sounds like the PO was one of those "I don't see any reason too pay
$400 for a water heater (or $12.95 for a switch) just 'cuz it has
'marine' on the label, when I can buy the same thing at Home Depot for
$150/$4.95." NEVER put any electrical components that aren't UL
rated for marine use in the same compartment as gas engines or fuel
tank.



As for HOW to do install it, you should be able to get an installation
manual from the mfr...what brand is it (that'll also tell me whether it
really is a household water heater or a marine unit)?

Thank you for your reply....

It's a GE......It's definitely NOT a marine unit. As for the installation, it's sitting on a piece of plywood in the engine compartment, with an extension cord run into the rear salon. Yikes.

The copper lines running to the engine compartment appear original, so I"m assumming a marine unit was there before. If I relocate it, I don't have enough space in the cabin for one this large. (probably why PO put in in the engine compartment). It looks like I'm in the market for a replacement......and it looks like my options are:

Buy a marine unit and install it properly in the engine compartment OR buy a smaller household unit and plumb it in the cabin.

Any suggestions?

Yikes is right! Not only the location, but the extension cord too.
Water heaters, refrigerators and freezers should NEVER be on an
extension cord, even in a house!



If you want to do things right, I'd bite the bullet and go with a
marine water heater. You can prob'ly find someone in your marina who
has room for the GE and will take it off your hands. The only
marine water heaters I recommend are Raritan. They cost more, but
outlast ALL others by literally decades:

Raritan Engineering | Water Heaters



As for size, unless you carry a LOT of water (a couple hundred gallons)
and have a lot of people aboard who insist on taking long showers, 12
gal should be adequate. Raritan water heaters are exceptionally well
insulated and hold water hot enough for most use for at least 24 hours.




Assuming you don't have a generator...If your engines have a
closed cooling system, go with a heat exchanger...then all you have to
do is run your engine for about 30 minutes to reheat the water. If not,
go with 115v/ac only.

In looking through the postings, I realize that it's a little late to be responding to a thread from last fall, but there [i]is a way around this type of situation. The problem with residential water heaters is that the thermostat on them isn't ignition-protected. So each time it makes and breaks to turn the electric power on or off, it makes a spark. If there are gasoline fumes present below deck, then "Boom!" This is only a suggestion on how to replace the thermostat with one that is ignition-protected, to remove the danger of blowing up the boat.

Raritan Engineering offers an ignition-protected water heater thermostat, Raritan part # WH16, that slips into the same spring clips that are used to hold in the thermostat on most residential water heaters. It ain't cheap ($89.60 factory retail price), but it is still cheaper than purchasing a whole new water heater - and it's definitely cheaper than taking a chance on blowing up the boat each time the heating element is turned on or off!.