Tankless Water Heaters

[Cheechako]

My Eccotemp L5 heater worked flawlessly for 2+ months. I have it mounted just below a hatch. Nice water temp adjustment. $120 includes a good shower nozzle. Auto ignition and a lot of safety features. I fail to understand how a simple 3 burner propane stove mounted next to a bulkhead is "marine safe" but a water heater with more safety controls is not........? If you leave your propane burner knob on and turn the solenoid off, then turn the solenoid on next time you want to cook, the stove spews gas out.... the L5 wont do that..... Oh well, it's ABYC and ther "here to help".........

[zeehag]

propane is only as dangerous as the human error involved in using it--same as natural gas and acetone.
the instant hot water units i have researched were good---i donot have or use them. i donot have hot water except from solar shower on my boat as yet--i will not keep a hot watwr heater that is a storage tank on my boat as they leak, and i donot enjoy finding my fresh water supply diminished without reason or my bilges filled with fresh water.
have fun and enjoy the hot water !! is a wonderful luxury!!

[Sandero]

If you have the space, a tank, the ones that work of engine heat exchanger and shore power offer several advantages:

No separate use or source of fuel
extra water storage
hot water at dock side when on shore power
no open flames

[capt_douglas]

my $0.02

Uses too much propane.
Propane can be hard to find
Another source of explosion

For hot water:
solar shower (6gal of scorching hot water, mix with 4 gal tank water for a warm toasty mix) - cheap and durable
engine heat exchanger hot water heater
maybe genset heated

[skipmac]

I bought a Showermate from Precision Temp (in Cincinnati). Haven't installed it yet but it looks great, all stainless, very well built, flow sensor auto ignite system.

Contacted a forum member that has had one for years and loves it. He spoke very highly of the support from the maker so I called them to find out. Got someone on the phone right away who was very knowledgeable and answered all my questions.
PrecisionTemp.com: For Recreational Vehicles and Boats

Now for the bad news. Get out the big wallet if you want one. New list is around $1500. What the heck, it's just a boat unit and a half.

[osirissail]

In the beginning - propane water heaters on boats were significant death traps. See: Carbon monoxide propane heater deaths
- The killer was carbon monoxide generated and not vented outside. Especially when installed in very small compartment of marine showers where the occupant closed the door for modesty.
- Several marine supply houses stopped selling them fearing liability lawsuits.
- Maybe the units have been modified to include exterior venting and carbon monoxide monitors, may not - in either case you should do some serious investigating about how the units deal with combustion gases and alarms for carbon monoxide levels. Sensing just oxygen levels may not be enough since it is the carbon monoxide that kills not the oxygen.
- - If the units are installed in a separate area from the enclosed shower compartment that would be much better but still the questions about venting and carbon monoxide build up need to be answered to your satisfaction.

[ggray]

osirissail, the site you reference concerns propane radiant heaters (which would be left on continuously), not propane water heaters. Of course , there have been deaths from propane water heaters, so the installation must be done properly.

I installed one outside in a locker, which should not have been a hazard, but I have to wonder whether there could be a danger even from one mounted in the head if one were minimizing water use, rather than taking long hot showers.

[osirissail]

There a lot of links to propane heater deaths and the purpose was only to alert everybody to the real killer - carbon monoxide. The original "instant water heaters" were gas fired and used all over Europe. They were mounted on the walls in the shower rooms. The units were transplanted to the heads in boats and installed without proper vents obviously because installing a vent through the cabin roof is not a simple affair. It has to use special insulated stainless steel or bronze fitting to keep from "cooking" the fiberglass cabin top along with being able to be sealed waterproof against sea water that occasionally washes over the decks and cabin while underway.
- - I wanted to strongly suggest the installation of Carbon Monoxide alarms in the cabin(s) where propane burners are being used. I have two - one installed near the galley and on back in the main sleeping cabin. They are the Safe-T-Alert self contained units and monitor the ppm of Carbon monoxide in these area of the boat. Cooking on propane stoves while the boat is sealed due to rain, etc. introduces carbon monoxide into the cabin. Also I have a Newport Diesel Cabin heater with is vented through the cabin roof but "chimney" style vents can develop leaks over the years. And any boat with a cabin roof chimney vent is also very prone to having the flue gas reversals due to gusts across the deck of the boat.
- - A blown main engine (or genset) exhaust hose can also introduce large amounts of exhaust fumes and CO into the cabin. A CO monitor is a cheap investment in keeping yourself and mate alive should CO build up in the cabin.
- - If propane instant water heater units were introduced again after being pulled from the marine market then hopefully they are better designed to prevent CO leakage. Literally, playing with fire inside a boat is a potentially lethal game.
- - The alternative, a engine and electrically heated hot water tank is so much safer by comparison. There is no "911" you can call from isolated anchorages or ocean crossings to come out and rescue you from CO poisoning.
- - But I am a firm believer in personal "rights" to live or die as you decide you want. But that aside, how about your children or mate who is also on board with you? Just because you are cognizant and alert to the dangers and take every caution, don't assume they also can or will do the same.

[capn_billl]

Tankless water heaters are nice. In a tropical area I rarely use hot water anyway. The sun heats up a length of hose hotter than I can stand it. I have been considering replacing the water heater I have that is wasting a cubic yard of engine room space with something else that does not hog energy. It seemsa waste to use so much power heating water on a boat that uses so much power cooling.

[Cheechako]

I would say if Propane hot water heaters are unsafe on a boat, then Propane cook stoves are REALLY unsafe. The propane Hot water heater runs typically for maybe 3 mins with an overhead hatch open. The stove may run 1/2 to 1 hour or more in an enclosed cabin (if not tropics), wind from the companionway has blown out my cook flame several times. The hot water heater only lights when there is a water demand. As with many things on a boat, it's a matter of safe management. True, an engine heated water tank is more foolproof, although you'll need to run your engine for hot water, unless you live at the dock...

whoops ...I guess I kind of repeated my self from May....

[zeehag]

i took out my water heater---the dang things always leak anyway-=-this one leaked at 2 of the corners, and i use a solar shower. is easy and doesnt require having water heated in side cabin house. i keep 2 on my boat and use one for 2 showers -sometimes 3. is a 4 gallon shower. often gets so hot i have to cool it down before using.