Source of hot water while cruising

[smj]

[quote]The two different risks are CO, on the one hand, and leaking propane and explosion, on the other. With enough ventilation, and with the combustion products properly vented outside, you've surely dealt with the first one. But the second one is much trickier.


I don't like propane on boats in general, but I guess a heater like this might be ok (ignoring the regs), if it were mounted outside the cabin where leaking gas can't drain into the interior, or mounted inside with a sealed burner and really good installation of the gas line (separate line all the way to the regulator, free of joints to the extent possible). And with a solenoid to shut it off at the regulator (not inside the cabin). Even then, there would be a certain risk which I would not be keen to take. With less than that, in my opinion the risk isn't really acceptable.




Getting back to the OP's question -- there are a plethora of different ways to produce hot water, well explained in this thread. None of them with the risks associated with propane.


These can be combined in different ways. I know a boat which has a calorifier heated by a small, dedicated hydronic heater (in addition to engine waste heat and immersion heater). Not the cheapest way to make hot water, but totally safe and simple in operation. By the time you go to the trouble to make a propane system really safe, you will have probably spent as much money as one of these would cost. [ end of quote]

So basically propane stoves shouldn’t be used on boats as well?

[waterdog]

We heat water with the inverter wired through a timer switch to the water heater. We set the timer to 30 minutes. The heater draws a little more than a kW for 15 mins or so and produces a tank of hot water. Battery drops from 100 percent to 98 percent and is replenished by 1100W solar system in a very short time.

[Dockhead]

Originally Posted by smj

. . . So basically propane stoves shouldn’t be used on boats as well?

I didn't say that. But since you asked -- I don't like them.


ABYC allow propane stoves under certain circumstances. If you follow ABYC and maintain your gas system carefully, and have a gas alarm, the risk is somewhat reasonable.


ABYC does NOT allow propane water heaters unless they have a sealed combustion chamber, completely separate gas lead, etc., etc.


So I would say the same about propane water heaters as I say about propane stoves -- comply with ABYC and have a gas alarm, and carefully maintain the system, and the risk is somewhat reasonable.


Obviously it's for each to decide himself, what risk is acceptable or not. Jim's propane water system fails ABYC standards in at least two respects, maybe three, and on top of that contradicts the manufacturer's own standards. Is that acceptable for anyone? I guess it's acceptable to Jim, but that is far from an acceptable risk for me.

[john61ct]

Are the lines used for (any) propane flexible ("rubber") or fixed (iron / copper)?

I assume the tank's in an outside locker, is how is the pass-through into the cabin handled, like a "clam" with electric wiring?

And when the fuel detector alarms, is there an automatic ventilating of the bilge / cabin space, and if so how are sparks prevented for that?

Whole idea gives me the willies

[Paul L]

Originally Posted by john61ct

Are the lines used for (any) propane flexible ("rubber") ......

Of course they are for a gimballed stove.

[Dockhead]

Originally Posted by john61ct

Are the lines used for (any) propane flexible ("rubber") or fixed (iron / copper)?

I assume the tank's in an outside locker, is how is the pass-through into the cabin handled, like a "clam" with electric wiring?

And when the fuel detector alarms, is there an automatic ventilating of the bilge / cabin space, and if so how are sparks prevented for that?

Whole idea gives me the willies

You and me both!




I would add to that, that since recently I am using a new NuWave induction cooker, just one burner, a quite cheap (less than £100) countertop unit.


What an awesome way to cook! If you imagine how good gas is compared to conventional electric -- so, I mean, sensitivity of your control of the heat -- induction is that much better again than gas. You actually set the temperature of the pan. And you can control the power draw without affecting the cooking temperature (just the time it takes to get there). It works so well that I am just not tempted at all to even turn on the gas. I run it off the inverter off batteries, or just coordinate extended cooking sessions with generator runs. Even with a carpy lead battery bank which has seen better days, it just works great.


I hardly see the need to take the risk of keeping gas on board anymore.

[smj]

What makes a sensibly installed sensibly used on demand propane water heater more dangerous than a sensibly installed and used propane stove/oven?

[Paul L]

Originally Posted by Jim Cate

What I think is a safe installation of a Paloma LPG flash heater, used solely for showering.

1. Local gas shut off valve, in closed position except when showering.

2. 3" vent line directly through the deck to a mushroom vent.

3. ventilation fan ducting cabin air into shower compartment any time power is on to the pressure pump for the shower.

4. Small port open to the outside air whilst showering.

5. Auto shut off if pilot goes out. Pilot only on whilst showering anyway.

It may not meet some arbitrary standards meant for folks who are not by nature careful, but I believe that it is quite safe in our hands. Has been in use for the 15 years we've been living aboard whilst cruising in this boat.

Jim

Where is the heater actually mounted? Is it in the head/shower compartment?

[Dockhead]

Originally Posted by smj

What makes a sensibly installed sensibly used on demand propane water heater more dangerous than a sensibly installed and used propane stove/oven?

Probably nothing at all if you install in accordance with ABYC and don't violate the manufacturer's requirements.

[john61ct]

Which is difficult if the mfg bans marine use

[Dockhead]

Originally Posted by john61ct

Which is difficult if the mfg bans marine use

This is true.

[smj]

Originally Posted by Dockhead

Probably nothing at all if you install in accordance with ABYC and don't violate the manufacturer's requirements.

I realize they're against the ABYC standards and also realize that the manufacturers recommend not being for marine use due to the lack of endorsement from the ABYC. The question is why are the on demand water heaters more dangerous than a propane stove?
I've purchased boats that were built in the UK and Australia and they had factory installed on demand water heaters. I know they usually don't recognize the ABYC but for some reason is this just a problem in the US or is it a problem with the litigious nature in the US?


Sent from my iPhone using Cruisers Sailing Forum

[john61ct]

Originally Posted by smj

why are the on demand water heaters more dangerous than a propane stove?

I don't think I'd have that in my cabin either.

Not saying **you** shouldn't, I guess I'm just more risk averse when it comes to that case.

But the very high flow rate is certainly a difference, and build quality / safety features vary greatly from one maker to the next, seen a lot of cheap cr^p in the ones sold for homes and camping.

Which is why I've asked for specific suggestions on instant HWS units the propane-accepting segment here consider good enough for usage inside their cabins.

[Cheechako]

Originally Posted by Jim Cate

What I think is a safe installation of a Paloma LPG flash heater, used solely for showering.

1. Local gas shut off valve, in closed position except when showering.

2. 3" vent line directly through the deck to a mushroom vent.

3. ventilation fan ducting cabin air into shower compartment any time power is on to the pressure pump for the shower.

4. Small port open to the outside air whilst showering.

5. Auto shut off if pilot goes out. Pilot only on whilst showering anyway.

It may not meet some arbitrary standards meant for folks who are not by nature careful, but I believe that it is quite safe in our hands. Has been in use for the 15 years we've been living aboard whilst cruising in this boat.

Jim

Well stated Jim. Like many things "boating" you have to use your brain.
I have used "on demand" hot water heaters on 2 boats. To my thinking they are as safe as a propane stove, maybe safer, as they have a multitude of safety controls built in. Use it just like you do a stove: dont leave it on, turn it on, take a shower, turn it off with a solenoid switch like you do your stove. No different than using your oven.
I always had mine right below a hatch I opened as well as having the cover and flue on one of them. The camping one was $107 complete and much better than a Paloma. Kept the water consistent temperature.
This debate has been as contentious as anchors over the years.
Eccotemp L5, up to a whopping $109 now!
https://www.walmart.com/ip/Eccotemp-...8aAir1EALw_wcB

[john61ct]

Does anyone incorporate hydronics / radiators for space heating?

Poor man's Webasto 8-)