Bosch Water Heaters

[Roy M]

Has anyone heard anything regarding the Bosch GWH-425-HN model (formerly the Aquastar 125HX)? I found some info at : Controlled Energy Corp. - Bosch Hydro-Ignition Tankless Gas Water Heater from ABS Alaskan, but I'm looking for some real world experienced users to verify. Thanks.

[wsvoboda]

Gas Water Heater

Here is another type water heater, It states it is ventless so can be installed anywhere onboard. Have not purchaced on at this time but because of wanting to live on the hook and cruising around I do not need to start my generator to heat my water tank. It ia also a little cheaper than Bosch. For practically reasons I would mount the unit in my lazerette where my current 6 gal water heater is now. Best of luck.

[Roy M]

Thanks, but I'm looking for an LP powered heating unit, not an electrical (especially 110 volt AC) heater. One option, though massive and heavy, and provides cabin heating, is ITR (ITR diesel hot water heater), another might be the Paloma which is tankless (but apparently now, unavailable). I would like to keep weight and volume as low as reasonable.

[JayH]

Originally Posted by Roy M

Thanks, but I'm looking for an LP powered heating unit, not an electrical (especially 110 volt AC) heater.

Look again, Roy. That is a gas unit. Comes in LPG or NG. Pilotless and ventless is real nice. According to the website, it uses a battery for the spark. I've read elsewhere that they have some type of "freedom" unit that can spark from water movement like the Bosch does, but don't see it mentioned. Bosch used to have a ventless unit, but I don't think they have one anymore.

[wsvoboda]

Thanks JayH, I was begining to think I gave in on the wrong unit. But it does mention on sailboats and cabin cruisers to have a vent system. They refer to West Marine for venting systems.

Perfect for Sailboats and Cabin Cruisers with active ventilation systems in place.
For More info on adequate ventilation practices for boats , RV's and mobile homes please link to:
http://www.westmarine.com In West Advisor use the Searchword: Ventilation

[Roy M]

Thanks, guys, for the clarification. A friend just gave me a copy of the January, 2010 issue of Sail Magazine, which has a pretty informative article on pages 60-62 on available waterheaters, with websites. Though I am initially leery about ventless systems, I will be looking further into them. Another thread, in the Multihulls section, described a brilliant means of improving the ventilation on my own boat, using the natural venturi caused by air flowing between the hulls of my Searunner trimaran (http://www.trimariner.com/searunner/Vent_Sys_1.html). It's funny how simultaneous, yet seemingly unrelated, conversations lead to the most amazing syntheses. I love Cruisers Forum.

[svtrio]

I lived aboard with a vented Paloma LP heater for 20 years. Never a lick of trouble. Used it for the stove and hot water, and served me well even in cold winters near the Chesapeake Bay. I bought a new one a year ago, but apparently they are no longer available in the U.S. I bought the new one on principle: I figured that something was bound to be ready to fail after 20 years, so I bought the new one as part of my refit from hell.

Under no circumstances would I operate this heater without a vent to the outside. Besides the dangerous threat of carbon monoxide in the boat, the release of additional moisture (and some by-product that would attach to every interior surface ) would be undesirable. I know that the Bosch and the Paloma are specifically excluded from being approved for marine use.

Roger

[TAREUA]

As someone in the plumbing industry, I sell a lot of on demand water heaters. In fact we now sell more on demand gas water heaters than tank type. As svtrio states, they don't have marine approval. This is more a result of the small size of the marine market making it not cost effective to pay to receive those approvals than anything else, from what they tell me. These modern on demand heaters (Rinnai, Bosch, Navien,Takagi, etc.) are quite a different beast than the old Paloma's. The modulation features make them much more fuel efficient and they have higher gallonage outputs. They are more complicated inside as well, and it would have to be seen how they would stand up to 20 years bouncing on the waves. I have also been warned by R/O dealers to look at water heater components if your water tanks are only going to be filled by R/o water.
I have an on demand heater in my house (rinnai) and love it, but I am still hesitant to put one on my boat yet. The previous poster is correct, in my experience, that vent free gas burners can put out a lot of moisture.

[SV Demeter]

Can anyone tell me why ABYC or whomever would not want to approve or condone the use of one of these newer style units? I always thought the issue was with having a pilot light. The newer units do not. How can they be any less safe than any other "approved" propane device like a stove?

Does anyone know the process for getting a device reviewed and approved? Does the manufacturer have to do this? Of course it must cost money or how else could the wonderful chaps at ABYC exist...

[Hope Light]

Does anyone have experience or an opinion on the instant 110v electric water heaters old by West Marine? It seems to me that the high amperage would be offset by the small time the water is flowing.
Thank you.