tankless hot water

[sundown]

I am considering installing a LPG tankless hotwater system on my sailboat. I would appreciate comments from anyone else who has gone this route (make,model, heater efficiency etc.) My local RV shop is suggesting a BOSCH shower mate but I have a feeling this is the Cadallac and I only need a Volkswagon.

I would like to take this op to wish everyone on this board MERRY XMASS and good trips in the new year

Bob Cameron
Patience IV

[AnchorageGuy]

several years back there were people that died using these units on their boat. Extreme care and proper units for marine use and correct installation is critical. IMO the risks do not out way the benefits. If these units were suitable for the marine environment all of the builders would be using them.

[Steve Pope]

Good installation and ventillation are the key to safe and successful use of these great pieces of equipment. There are many yachts that use then here in NZ, "I" am not aware of any disasters using them on the water.

[Southern Star]

I agree Steve. I have one (as well as a typical 120 V/heat exchanger tank) on my Cat, and know that the Niagara 35's and Nonsuch boats all were so equipped. I have never heard of disasters or fatalities, although I suppose like propane stoves, it would be possible with improper installation/maintenance.

Brad

[MidLandOne]

Agree with as Steve Pope says.

We have one but in our case we also have a storage system heated from the engine coolant and if shore power available by that too. When we are away we normally run the engine for charging every day and find that gives us plenty of hot water throughout the day for bathing, etc. For small amounts of water though, such as for dish washing, we do heat that on the gas cooker as that is more frugal with our fresh water and we carry much longer duration of gas than we do of water.

So given that situation we find that we never use the tankless system and if building another boat would just go with the storage system.

[Latitude9.5]

I have a precision temp marine hw heater, we love it. It's positively ventilated and turns off the gas if it can't ventilate or light.

[Sandero]

I prefer the electric with engine heat exchanger. It provides additional tankage as a bonus! No additional fuel. No possibility of fire, or accident. No noise. Hidden away in some inaccessible location. No moving parts. Provides sufficient hotwater for cruisers who run their main engine each day, which is common for refer cooling, batt charging, anchoring (windlass).

I don't like to run the engine when not making way, but since we need to keep our batts topped and we use amps, and out alt sources don't cut it and out refer is engine drive and we make hot water at the same time and we can use the vacuum on the inverter when then engine is running and clean the dishes with hot water at the same time (after breakfast or after dinner)... it all works out. The engine is used to convert diesel in refer cool, electricity and hot water... and if we need to do a fuel or water top off we do all this while making way.

Seems to make sense.

[44'cruisingcat]

For our gas hot water system I considered a Bosch style "on demand" gas heater, but currently I am looking at using one of these:

Hot Water Systems - Northcoach Equipment

For a couple of reasons. It has the option of an electric element, so in a marina you can have hot water on demand without using up your gas. Also I can run the gas burner when it suits - ie first thing in the morning, and maybe again in the evening. The rest of the time I can have the gas system turned off, but still have (admittedly a limited amount) hot water available.

The system is also light, and has a stainless steel tank.

[rebel heart]

Dickinson (makers of Newport heaters) offers a single and dual coil water heater that mates with their heaters. It's another option. I've been thinking about installing one, since my showering needs normally end up in these categories:

- Hot and sunny outside, use a solar shower, brining the wand through the head/shower portlight.

- Cold and/or crummy outside, using the cabin heater. This is when it would be nice to have some hot water from the heater.

- Bug spray bottle & some hot water from the stove (mixed with regular water) for everything else.

- Marina showers when available.

Between those four options, things work out well. I want to install the water coils once I've found someone who can recommend them, since it seems like the times I would want a hot water shower and wouldn't be able to get it from the solar shower is when I'd have the cabin heater on.

Engine driven isn't an option for me. The only thing that's engine driven on my boat is the prop.

[Pblais]

We have a BOSCH ventless design (they only make one). The ODP (Oxygen depletion senor cuts off the LPG when Oxygen is too low). I would not call it a Cadillac but a good design. I'm not sure what a cheap one would be. It is very easy to service and maintain.

You light the pilot with a nice safe interlock system that is very easy to use. I don't leave it lit all the time because even my wife can light it as required. The interlock is after the normal solenoid. Once lit, it fires as the water flows and shuts off when you stop the flow. A couple teenagers can drain the water tank in short order. I would say that's the bad part. You really can use all the hot water you want. Mine was installed in 1991 and works as good as new. Many hot water tanks don't last that long.

All the other instant solutions will require a vent. Not a bad thing but yet another hole in the deck to leak.

[Microship]

My boat came with a Bosch that works beautifully and was new in 2002... but the surveyor unfortunately saw fit to note that it has an open flame pilot instead of the newer piezoelectric type... so now my insurance company is requiring that I change it. Anyone need yesteryear's model?

Steve

[Celestialsailor]

I have had the "Volkswagen" Paloma LPG heaters. I mount them by the companionway. I only use it with the hatch open. I also have a gas sniffer to alert me to any propane in the bilge...very important.

[Sunspot Baby]

There are some previous threads on this discussion worth reading. I have had a Wolter and now a Bosch. The Wolter was on the boat when I bought it after a couple of repairs I decided to go with new. I was plumbed for gas so went that way.

I can't imagine running enough hot water to cause oxygen depletion, but keep a CO detector in the head just in case.

George

[Pblais]

I can't imagine running enough hot water to cause oxygen depletion, but keep a CO detector in the head just in case.

The two are unrelated. The CO detector measures carbon dioxide (poisonous) and the ODP measure oxygen (you need to breath something). You really need both. CO detectors are about to become required on new boats. Just a good idea in any boat. I find the built up heat requires opening a port. It does dry out the shower quite well and quickly too. You can shower when it 40 F outside and stay warm as well.

[Stevens 47]

Paul,

Can you tell me about the maintenance of the unit. Have been reading the specs very impressive, states that at 2 gpm the unit will use 20lbs of lpg to heat 940 gallons of hot water. Have not been able to find the max hot water output can you give me a idea. The up front price at 1450 is pretty steep but if it is as efficient as the specs says should pay for it self in a couple of years and would be allot easier than electric.

Jack