water heater

[pboldra]

In the process of refitting a 38' sailboat. Can anyone recommend a LP water heater? Either tank or tankless.

Thanks!

pboldra

[GordMay]

Greetings and welcome aboard the CF, pboldra.

[sailvayu]

There is no marine approved propane water heater for many reasons. Basically they are just plain dangerous on a boat. I am sure if you do a search you will find many threads on here about it. Go with electric with an option for engine heat exchange. I am sure there will be some to argue with me on this but the facts are the facts and there are reasons why you will not find any approved for marine use.

[Dsanduril]

For a tank type water heater I could see that argument, but for a tankless, what really is the difference between that and a propane stove on a boat? I know some people are opposed, but 10s of thousands of boats operate with propane stoves just fine. And with a stove the combustion products end up in the cabin, with a tankless water heater they get vented outside.

With a proper solenoid valve installed (as with a stove), no reason that a tankless can't be operated with propane shut off at the tank except when in use. Heck, you could put a flow switch in series with the manual switch, so that the solenoid would only operate when someone turned it on and there was water flow in the shower. I could see finding a ventilated, separate compartment to install it in being a problem on most boats, but that's a different question.

And, while expensive, this heater is designed for marine installation:

ShowerMate M-550

[sailvayu]

Well that heater is interesting but I do not see UL or ABYC approval on it. maybe they do not list it. A heater and stove are very different in that a stove is a attended appliance with open ventilation, a water heater is not and that alone is a big difference. I am not going to get into arguing this all over again it comes up every few months. The big problem is really when someone takes a house or camper heater and sticks it into a boat. If the ShowerMate is approved great, it maybe a good thing as long as the whole installation is done correctly.