Anyone use a Tankless Water Heater on their boat?

jwrape · Post by **jwrape** » Tue Jan 19, 2010 10:50 am

I don't remember if I have asked this here before but has anyone coverter from their HUGE bulky conventional hot water heater to a tankless on their boat.
I'm considering it but don't know which electric water heater would work the best.

ready123 · Post by **ready123** » Tue Jan 19, 2010 11:18 am

Electric??
Do they not require 220V and a lot of power.... 80 Amps to work effectively? How will you supply that on the boat? Size of genny reqd:?

Do you use that much hot water on the boat to justify that kind of move?

I find a sun shower to be a much better investment.

jwrape · Post by **jwrape** » Tue Jan 19, 2010 11:26 am

ready123 wrote:Electric??
Do they not require 220V and a lot of power.... 80 Amps to work effectively? How will you supply that on the boat? Size of genny reqd:?

Do you use that much hot water on the boat to justify that kind of move?

I find a sun shower to be a much better investment.

60 amps tops, but I won't be using the Generator to operate it, only shore power. Not sure what kind of panel power I have onboard. Need to look.

I curerntly have a HUGE (20-30 gallons) conventional water heater onboard now. What ever it pulls, I should be able to replace with a tankless. It actually does already run on Generator as well as shore.

It needs to be enough water to support a Galley and two full bathrooms.

jwrape · Post by **jwrape** » Tue Jan 19, 2010 11:36 am

For instance:
http://cgi.ebay.com/TITAN-TANKLESS-WATE ... 45e9511438

Specs:
Features and Specs:

Whole house capacity- 3bed/2 bath (One shower at a time)
4 GPM
Thermostatically control temp on front cover
60% energy savings vs. conventional electric water heaters
99.5% efficient
10 year warranty on water carrying components- 1 year on rest of unit
Space saver
On demand water control- equals unit longevity and savings
For use with hard, soft, well or city water
Problem free installation
Most efficient and practical product of its kind on the market
Steel outer/ copper-brass inner casing construction (no plastic or pvc parts)
UL approved #499
ANSI-Z 10.03 certified
Dimensions: 10" high x 7" wide x 2 3/4" deep
200-220 vac @ 50 amps
Dual heating chambers
Simple instructions for installation ease

OR the N85
Features and Specs:

Designed for use in southern region condos, apartments & mobile homes
3 GPM (Will service your entire apartment, condo)
Thermostatically control temp on front cover
60% energy savings vs. conventional electric water heaters
99.5% efficient
10 year warranty on water carrying components- 1 year on rest of unit
Space saver
On demand water control- equals unit longevity and savings
For use with hard, soft, well or city water
Problem free installation
Most efficient and practical product of its kind on the market
Steel outer/ copper-brass inner casing construction (no plastic or pvc parts)
UL approved #499
ANSI-Z 10.03 certified
Dimensions: 10" high x 7" wide x 2 3/4" deep
200-220 Volts @ 38 amp draw (Only requires a 40 amp dual pole breaker)
Dual heating chambers
Simple instructions for installation ease

ready123 · Post by **ready123** » Tue Jan 19, 2010 12:06 pm

You have 220V 40 amp service at your dock?

jwrape · Post by **jwrape** » Tue Jan 19, 2010 12:08 pm

ready123 wrote:You have 220V 40 amp service at your dock?

I have 2 seperate 110v connections from my dock that supply my 2 sided panel on the boat. BUT it's prolly not 220v come to think of it.

ready123 · Post by **ready123** » Tue Jan 19, 2010 12:29 pm

jwrape wrote:
ready123 wrote:You have 220V 40 amp service at your dock?
I have 2 seperate 110v connections from my dock that supply my 2 sided panel on the boat. BUT it's prolly not 220v come to think of it.

No probably about it... you have 110V.

Stripermann2 · Post by **Stripermann2** » Tue Jan 19, 2010 12:30 pm

Won't work...
Check out this thread from awhile back...I was trying to figure out how to make 220/240 volts out of shore power.

http://www.trojanboats.net/wforum/viewt ... =220+volts

jwrape · Post by **jwrape** » Tue Jan 19, 2010 12:42 pm

Stripermann2 wrote:Won't work...
Check out this thread from awhile back...I was trying to figure out how to make 220/240 volts out of shore power.

http://www.trojanboats.net/wforum/viewt ... =220+volts

Yea, I see.... Might look into an individual 120v unit under the floor to take place of the giant water heater.
Just not sure if the .5 gallons per minute would be enough for a shower. The faucets would be fine but the showers might not tolerate it.

Something like this maybe
http://www.pricelesshomecenter.com/prod ... category=0

g36 · Post by **g36** » Tue Jan 19, 2010 8:46 pm

i have found that if the water is hot when leaving the dock the water will stay hot for quite sometime at anchor, sure you have too..my water heater doesnt have the exchanger for heating the water from the engine however if you get rid of your storage type water heater you will loose this as a convience too, you might conider a smaller unit if the big one is too much in the way. yes the gen set will heat the water again in but its nice to have some hot water without doing anything at least for a while. i dont run my generator unless i really need too i have batteries and invertor for just about everything . the tankless would be nice but if the generator wont run it i think it would be a waste. but thats my thought i like my boat to be self suffient with everything on board that i can

prowlersfish · Post by **prowlersfish** » Tue Jan 19, 2010 10:03 pm

Do you really what a water heater that you can only us when you shut off everything else in the boat before you use it ? you want to take a shower so you turn off the a/c , tell the wife to stop cooking ? The water heater you have now draws maybe 15 amps or less. ( mine is 12 amp) .

Also those units can only heat up the water so far if your water in the tanks is very cold you may not get very hot water , if the water in the tanks is warm you could get burned , scary if you have kids

ready123 · Post by **ready123** » Tue Jan 19, 2010 11:22 pm

Maybe you should go this route... Bosch Aquastar 125HX
http://www.kk.org/cooltools/archives/000593.php

prowlersfish · Post by **prowlersfish** » Tue Jan 19, 2010 11:27 pm

a propane water heater ? on a boat ? is is C.G. or UL for marine use ?approved ?

alexander38 · Post by **alexander38** » Wed Jan 20, 2010 3:47 am

get a 6 gal with exchanger set up small and at 190f you'll have hot water almost all day. Defender sales them for $200.00 to $230.00

jwrape · Post by **jwrape** » Wed Jan 20, 2010 6:56 am

I think I will stick with the type I have already after looking around.

The biggest problem will be getting the old out and a new in. The door is 20" wide and the water heater is MUCH bigger. I hate it but I'm gonna have to take the top hatch off and the headliner out to replace the water heater. I'm ot looking forward to it. Hopefully it will hand on for a while. It still works perfectly, just rusted at the bottom.