anyone use tankless water heater on their boat?

jwrape

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My old Water heater is soon to need replacing. I want to use a tankless water heater if possible. Anyone done this before?
 
Not really possible, unless you are thinking propane and then you'll have to vent it some how. If you had a house boat that might not be a problem. The specs on an electric require 220 volts, 40 amp. and that gets you a 45 degree rise for 1.25 gpm. I don't think there a very many marinas that have much more than 220 volt, 50 amp power available. 1.25 gpm is not really enough for a shower anyway.
Tankless water heaters really don't save much in your house unless you can put enough of them in to prevent running alot of water just to get hot water to the shower. Tanks today really don't lose that much, I know when I go on vacation and shut mine off when I come back after a week water is still warm. When I leave my boat on Monday and shut electric off to the tank, water is still very warm on Friday when I get back.
 
Oh well, I was really looking forward to saving the space in the beldge, but I guess when it's time I will replace it with the same type. Don't have ANY idea how I will get it into a 20"door though. I guess I will be yanking my top off to replace it.
 
quote:

Originally posted by jwrape

Don't have ANY idea how I will get it into a 20"door though. I guess I will be yanking my top off to replace it.






Don't know what type and size water heater you have but I just replaced mine with a Seaward F1200, 11 gallon heater. it's only 16" wide so went through the door and into place without any trouble at all.

I also looked at tankless heaters and found the power demands just WAY to high to work.

Bob
 
If the replacement is on a diesel or goes into a sealed seperate compartment on gas ( seperate from the fuel tanks, lines, or engines). We've been replacing them with tanks bought from Home Depot, or Lowe's that's what came from Trojan on my 36ft.
 
If you are diesel,you can get by with a regular water heater like Jim P. mentioned.I replaced mine about 3 years ago. My floor compartment opening was only 20 inches.After shopping around,I found the one sold by Lowes is only 20 inches wide.The one at Home Depot is 21-21&1/2.I hope this helps.
 
A quick rule of thumb for tankless water heaters is that they require 3.0 Kw to raise the water temperature 20* for 1 gpm of flow. So if you double the tempeature rise to 40*, then 5.0 Kw of electric are needed (220volt x 25 amps or 110volt x 50 amp). 1 gallon per minute may not be enough to run a shower.
 
Actually, there are tankless water heaters for use in boats...we have them available from one of our suppliers. They retail at about $350
 
Yes, there are tankless water heaters designed for boats and there are several available on the market. The problem is, that for the most part, the electric versions simply don't work! The 115 volt models are virtually useless, and the 220 volt models draw so much power that they really aren't practical onboard a boat.

The only ones that are any good are those that are propane-fired. However, most people don't want propane on their boats, due to the explosion hazard that is associated with it.

So for the average boater, the heated storage tank type of water heater is the most practical.
 
quote:

Originally posted by Vic Willman

So for the average boater, the heated storage tank type of water heater is the most practical.





What Vic said +1.

Also, get a storage tank type water heater with a heat exchanger and you get hot water while underway with no additional power requirements at all. True, the capacity isn't enough for a 15 minute steaming shower but every little bit helps. :)

Bob
 
I installed one on my old carver 28 mariner. It was less than $200 from the wal-mart of boat stores. The idea was nice, the space savings was great, but it simply sucked. It was 110 volt and everything had to be shut off when on a single 30 amp line. I would NOT recommend this type of product.

Jim
 
I have the 25 amp elect. It works good in the summer and just fair in the winter.
I bought it at West Marine with a 5 year warranty. When it went out after 2 years, I brought it back to WM
and they gave me the phone number and a contact to call the manufacturer. I called them and they needed the
model and serial numbers off the unit. I got it and called back. They said this unit was manufactured over
5 years ago and was no longer under warranty. They would not deal with me, even though I had the receipt with
the purchase date. They only work with the manufactured date.
I went to WM and let them know I was not happy. They told me to take a new one off the shelf. It also lasted
about 2 years. I got another one from WM and I am going to put it on soon.
It is the only water heater that will fit in my boat. A tank one will not fit anywhere. Once the warranty is
gone, I am not sure what I will do since I don't have room for a 5 or 6 gallon water heater.
I do have to turn off the a/c due to the high amps when running the water heater, but that is not a problem
so far.
 
I looked at this when we did the refit/repower.

Water heater was about 25 years old.

Went with the 12 gal water heater with the heat exchanger.

That way if you run the engine, you have hot water.

The biggest plus is that running te engine gives you hot water for HOURS without electric AND it gives your water a quick jump start to hot temps.

The only time we need to flip on the water heater is when there are multiple showers or we're on the hook/at the marina for an extended stay.

RWS
 
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