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Semi-Instant hot water heaters

Posted: Sun Mar 25, 2012 1:37 pm
by jefflaw35
Alot of you have showers so i would think you are using water heaters. I found a site that makes very small ones being used on boats. Prices look to be around the 200$ and up, plus install material. Has anyone upgraded to this system. My home is gas. This read electric. Instant hot water from electric???

Posted: Sun Mar 25, 2012 2:10 pm
by prowlersfish
Look at the current draw and how much they heat the water , a lot of power and liltle heat IMO '

Untill I got in the 30+ foot range i use something like this

http://bestcampingshowers.com/camping-s ... shower-bag

Posted: Sun Mar 25, 2012 3:08 pm
by Big D
Jeff, considering you mentioned in the past that you will be using the boat for fishing and thus I suspect trolling, why not get a marine hot water tank with heat exchanger that you can plumb into the engine's cooling system. As long as the engine is warm, you'll have hot water. At shore or off genny, it'll run off electrical. You'd also be surprised at how long they retain hot water once heated up and you've left the dock. Also adds to on board water capacity.

Posted: Sun Mar 25, 2012 3:10 pm
by aweimer
I have a 20 gallon heater, what i like is that you turn it on for an hour and you have hot water for most of the day.

Posted: Sun Mar 25, 2012 3:12 pm
by Big D
aweimer wrote:I have a 20 gallon heater, what i like is that you turn it on for an hour and you have hot water for most of the day.
+1

Posted: Sun Mar 25, 2012 3:13 pm
by rbcool
aweimer wrote:I have a 20 gallon heater, what i like is that you turn it on for an hour and you have hot water for most of the day.
+1

Ron 8)

Posted: Sun Mar 25, 2012 3:34 pm
by alexander38
aweimer wrote:I have a 20 gallon heater, what i like is that you turn it on for an hour and you have hot water for most of the day.
bang on ! 6 gallons of 180 degree + water goes a long way...no need of making a new wheel when the old one is round....

Posted: Sun Mar 25, 2012 4:18 pm
by prowlersfish
aweimer wrote:I have a 20 gallon heater, what i like is that you turn it on for an hour and you have hot water for most of the day.

I have a 12 and it does the job.

Posted: Sun Mar 25, 2012 5:47 pm
by jefflaw35
Thanks guys. Im sure you know this idea is about the hands. When they get. BAd i need hot water to bring them back to life. On the little boat i empty engine water into a bucket. Now i have a sink! Lol oh luxury!! Thanks for the answers..

Posted: Sun Mar 25, 2012 7:45 pm
by prowlersfish
Many marine water heaters can use engine coolant to heat the water, no shore or genset power needed .

Posted: Mon Mar 26, 2012 11:29 am
by larryeddington
Jeff,

I went through this same decision making process, have not made a purchase yet, but ruled out the electric instant on such as seen in West Marine Catalogue. 28 or so amps at 110. I have decided that I will use a dual type heat source for water heating as mentioned by above. Your engine is FWC so gives you hotter water to heat the water tank with. My hoses will run from Intake manifold beside T/stat to the water heater and back into one of the two ports that now have plugs in them. These two ports are for returning water. The old one was electric only. I like the idea of heating with waste heat from engine.

Posted: Mon Mar 26, 2012 6:18 pm
by jefflaw35
Would this make it more difficult to notice if you are over heating in the motor? Will it play games with the guage? If you do have engine problems and over heat, will you be fixing more than just the motor?

Posted: Mon Mar 26, 2012 6:27 pm
by larryeddington
IMO I cannot see any downside. It would seem if the hot water tank is cold it might take a little longer to get the engine up to heat but not probably a big deal, in fact it might help engine cooling as it is another heat sink. The hot water tanks have a pressure temp valve that can open in case the water overheats same as one in your home. Others use this setup with no problem. If the engine is overheating it is due to poor cooling from raw water or low freshwater antifreeze mix. IMO :)

Previous thread regarding:

http://www.trojanboats.net/wforum/viewt ... ght=heater

Posted: Mon Mar 26, 2012 7:57 pm
by Big D
jefflaw35 wrote:Would this make it more difficult to notice if you are over heating in the motor? Will it play games with the guage? If you do have engine problems and over heat, will you be fixing more than just the motor?
No, no, no and no! Just about every boat made today with hot water system has one.

Posted: Mon Mar 26, 2012 8:13 pm
by jefflaw35
thanks guys problem solved! and I will say, This is exactly how a post should go. Pro-con and to the point.