# Propane Water Heater



## JiffyLube (Jan 25, 2008)

I'm thinking about installing one of those pilot-less propane water heaters that makes instant hot water, and I'd be interested in hearing the pros and cons of these devices by people that have them. Do they make enough hot water on demand to replace a conventional marine water heater?


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## Maine Sail (Jan 6, 2003)

Some of them can make plenty of water but unless they are sealed combustion with an intake and exhaust vent your insurance comapny won't like it much as they are not an approved appliance by marine standards. I know two people who have been told to remove on-demand "ventless" propane water heaters during an insurance survey. Something to think about before installation.


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## mitiempo (Sep 19, 2008)

This is the only propane water heater I have ever seen that has no pilot light and a closed combustion system.
Precision Temp Boat Tankless Hot Water Heater. Gas Marine Water Heaters. Propane Boat Hot Water Heater


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## Minnewaska (Feb 21, 2010)

Oh the horror.......

Seriously, you would require a charged propane line in the boat at all times and a flame would be ignited outside your view. This is unlike the galley, which is manually shut down when not needed and can/should be monitored when lit.

Sorry, it just sounds like a bad idea.


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## JimPendoley (Jan 17, 2005)

*Oh the horror*

I've got a propane water heater that I live aboard with quite comfortably. I also have a Dickinson Marine Propane Heater and a Seaward Stove/Oven. Given all of the saftey features, no pilot, O2 depletion shutdown-I feel that the risk is minimal. Seems a lot safer than running my oven...As for venting, I open a port in the head where it is located and enjoy a hot shower. I've also got a propane sniffer wired to a solenoid for auto shutoff in case of a leak.

That said, I'm sure an insurance company would balk, but its a risk I'm comfortable with. Living your life according to the dictates of an insurance company can be pretty limiting...
YMMV


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## Minnewaska (Feb 21, 2010)

My horror comment may not come across correctly. It was tongue in cheek. Propane issues usually bring out the horror in us, when there are virtually no propane fires compared to other sources.

That could be due to better safety measures than electrical systems and engines. However, I don't like the potential of propane leaks down below. I've gotten in sword fights over how far one must go with the BBQ outside on the rail, where I seem to be less risk adverse than some others.


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## Waltthesalt (Sep 22, 2009)

I have a bulkhead mounted Wolter instantaneous heater. It's a compact unit, I wouldn't have the space for the Precision unit. 

I built separate control box (Radio Shack Project box) for the unit and installed it in the shower area. This includes power switch for the box, power switch for the unit and a switch for the propane solenoid. I also have a CO sensor/alarm in the shower area. 

Per ABYC the heater has its own separate hose from the propane tank manifold and its own shutoff solenod valve controlled from the shower control box. So the propane line isn't pressurized except when the unit is in use. My unit and I think most curent RV units don't use pilot lights but have a 12 "igniter" that fires and starts when there's water demand. The gas shuts off when the demand stops.

My pressurized water system only serves the instantaneous heater, but my boat is small and the telephone shower head can reach to the head and galley sinks. The water's delivered at an adjustale usable temp so ther's no need to mix it with cold water. Those sinks use hand pump faucets as thier normal supply. I use two separate water tanks and supply systems as I didn't want to run the risk of a valve in the pressurized system being cracked open and unitnetionally pumping down the tanks. The hand pumps can switch between tanks but the pressurized system can't be cross connected.

My heater vents thru a 3 in. exhaust pipe thru the cabin top. Intallation requires a specific minium exhaust vent distance to get requisite flow so it doesn't back up. I think Wolter stopped production when someone was killed becase the unit wasn't properly vented and the exhaust gas backed up into the shower stall.

Instanteous water heaters for boats were once popular. The current trend appears to be a heater that us heated by engine cooling water of 112V heating elements in port. This requires quite a bit more space space that a bulkhead unit. I'd have to give up a quarter berth.

Wolter is long out of production now. I recall that Poloma, a japaenese company was a popular maker boats propane heaters. These had a pilot light however. From what I read on Sailnet, people with old Paloma heaters were being replacing them with Excel, heaters (no pilot light). Check out the thread.

As my Wolter is on its last legs the Excel looks like a reasonable replacement.


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## Waltthesalt (Sep 22, 2009)

Someting else I or got. My heater/shower is in the head which has an opening ports and a hatch. I have have a sign on the heater that these should be partially open if the heater's being used. I woldn't put one in a head without good ventillation. Alternatively the heater could be located in the cockpit area. Wolter had a unit desigend for it. My control box also has a 1in diameter red light that's when it's energized


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## MacGyverRI (Nov 14, 2007)

Waltthesalt said:


> Alternatively the heater could be located in the cockpit area.


I'm going to mount an "EZ-101 tank less heater" (made for camping/outdoors) on my back rails, it's about the size of a MOM unit and was $140.

I also have a "Safe-T-Alert" Fume Detection system inside for the Propane heater.


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## jimrafford (Jan 7, 2011)

I'm currently in the process of installing the Precision Temp heater. I'm also installing a propane detector in the area where the heater will be. We're pretty conservative about our hot water use but I'm tired of no hot water to do the dishes after navy showers. Will know in a couple days how well it works.
Jim


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## mitiempo (Sep 19, 2008)

minnewaska

There are few propane fires - more propane explosions. 

Seriously though.
I think if installed in a compartment with it's own air intake and a vented exhaust a tankless propane heater without a pilot light would be safe and an insurance company should not have an issue with it. I think Walt's installation comes close. 

With solenoids, sniffers, and common sense propane is a great fuel for cooking, heating, and hot water. I currently don't have hot water aboard but on a previous boat had a Rinnai propane water heater installed in the galley very close to the main hatch. I loved not having to mix hot and cold to get the right temp. 

The Precision heater seems to be the ideal solution that may please ABYC as well as the insurance companies.


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## JiffyLube (Jan 25, 2008)

Thanks for the feed back guys, and this is what lead me to ask about these propane water heaters.

On our boat we had a Seaward 5 or 6 gallon water heater located under a salon floor board, behind the engine on a shelf over the transmission. I had some work done on our boat, and part of the work was replacing the old PSS with a new one. The shelf the water heater was on made access to the PSS almost impossible, so I took the water heater and shelf out for good access. Now that the shelf is out I really hate to lose the access to the PSS, so I've been thinking about relocating the water heater.

There is no other place I can put a new conventional water heater other than in a cockpit lazarette (which I don't want to do), and keep the water heater lower than the engine coolant reservoir tank. The one place I wanted to put it under the large, raised quarter berth would place the top of the water heater at least two feet above the engine, and I'd have to install another reservoir slightly higher than the water heater. Then use a higher pressure cap on the present lower reservoir, and a lower pressure cap on the higher reservoir. The problem with this is, I can't think of a good location that high for a reservoir that I can access easily. So that make me think about another option, and that's why I asked about a pilot-less propane water heater.

I've heard about insurance concerns before, so that is the one major thing that's holding me up more than anything else. I'm going to communicate with our insurance company, and see if they maybe have approved models of propane water heaters they will insure for.


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## WanderingStar (Nov 12, 2008)

jimrafford said:


> I'm currently in the process of installing the Precision Temp heater. I'm also installing a propane detector in the area where the heater will be. We're pretty conservative about our hot water use but I'm tired of no hot water to do the dishes after navy showers. Will know in a couple days how well it works.
> Jim


I'm also interested in that unit. I look forward to your report.


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## MacGyverRI (Nov 14, 2007)

JiffyLube said:


> Then use a higher pressure cap on the present lower reservoir, and a lower pressure cap on the higher reservoir. The problem with this is, I can't think of a good location that high for a reservoir that I can access easily. So that make me think about another option, and that's why I asked about a pilot-less propane water heater.
> .


All you would need is a bleeder screw at the high point (like foreign cars have) and the water pump would push the water up to it. Once the loop high point was purged (while the engine is running) it would be fine. Changing pressures wouldn't be a good idea.


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## JiffyLube (Jan 25, 2008)

MacGyverRI said:


> All you would need is a bleeder screw at the high point (like foreign cars have) and the water pump would push the water up to it. Once the loop high point was purged (while the engine is running) it would be fine. Changing pressures wouldn't be a good idea.


So you think a higher reservoir tank would not be needed? What about when I wanted to check the reservoir level on a tank lower than the water heater? Wouldn't the weight of the water in the water tank that is higher than the reservoir make the reservoir overflow?


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## MacGyverRI (Nov 14, 2007)

JiffyLube said:


> So you think a higher reservoir tank would not be needed?
> 
> What about when I wanted to check the reservoir level on a tank lower than the water heater? Wouldn't the weight of the water in the water tank that is higher than the reservoir make the reservoir overflow?


I don't think, I know 

It's a "closed loop system" and unless you open that bleeder screw, the water will stay in the loop even when you take the cap off. You're not talking raising it 3-4 stories, only a few feet at best and the engine water pump will let you bleed any air out.

Take a 50' garden hose and fill it up w/ water, hold both ends into a barrel of water and have someone lift the mid point 10-20', it's still full of water isn't it? "Closed loop"


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## JiffyLube (Jan 25, 2008)

MacGyverRI said:


> I don't think, I know
> 
> It's a "closed loop system" and unless you open that bleeder screw, the water will stay in the loop even when you take the cap off. You're not talking raising it 3-4 stories, only a few feet at best and the engine water pump will let you bleed any air out.
> 
> Take a 50' garden hose and fill it up w/ water, hold both ends into a barrel of water and have someone lift the mid point 10-20', it's still full of water isn't it? "Closed loop"


First I have to say I goofed up when I said "Wouldn't the weight of the water in the water tank that is higher than the reservoir make the reservoir overflow?" I don't know what I was thinking when I said that The water in the water tank (water heater) is on a seperate system, so it would have no bearing on the engine coolant reservoir level.

I'm thinking that a small circulation pump in the coolant sysytem might be good to have in assisting the water pump...what do you think?

Water heater manufactures recommend that water heaters be installed as close to the engine as possible, and lower than the engine if possible. I guessing the "close to the engine" part is for less heat loss to the water heater, but I'm not sure about the "lower than the engine" part.


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## MacGyverRI (Nov 14, 2007)

JiffyLube said:


> First I have to say I goofed up when I said "Wouldn't the weight of the water in the water tank that is higher than the reservoir make the reservoir overflow?" I don't know what I was thinking when I said that The water in the water tank (water heater) is on a seperate system, so it would have no bearing on the engine coolant reservoir level.
> 
> I'm thinking that a small circulation pump in the coolant sysytem might be good to have in assisting the water pump...what do you think?
> 
> Water heater manufactures recommend that water heaters be installed as close to the engine as possible, and lower than the engine if possible. I guessing the "close to the engine" part is for less heat loss to the water heater, but I'm not sure about the "lower than the engine" part.


I understood your concerns about height with the explanation, I've been doing this almost 40 yrs now. 

The water hose thing I posted is an example of how high you could go when it's was air free w/ the bleeder. Theoretically the water resistance/height is negated by the fact it's closed loop and the actual height is the small difference (if any) between the inlet and outlet on the motor.

Welcome to Fluid Dynamics 101 

Think about a sump pump (not really bilge pump) if used on a boat. You put the pump in the lowest part of the bilge, then hold the hose at the high part of the transom (5-7' difference?). Flow will increase IF you put the discharge nearer to the actual ocean/lake/water. That's called "lift" and doesn't apply here because that's an "open" system. So, the extra pump really isn't needed in your or most peoples boats!

The Manuf. wanting it lower is just to make it "self bleeding" but you will still need something like a baseboard heater elbow fitting w/ an air bleed on it to make it work correctly since it's initially higher. Put that on the "outlet side" or the higher fitting on the tank.

Remember, It has to be bled while running a bit higher than an idle to get the pressure up so you can bleed it. It may even self bleed depending on height/pressure. You will need to add water initially after starting the motor to fill the lines and coils inside the heater. After it takes the extra water you can try bleeding it.

Most Engine water pumps will usually push about 10-15 lbs. off the discharge side of the pump or near the thermostat area while running. A raw water pump could go higher than 20+ lbs. (at the outlet) because it's a rubber impeller and almost positive displacement. This isn't radiator cap pressure but flow pressure to circulate.


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## stuartbell (Nov 14, 2004)

I put in an Excel in Sept. 2010. First one was dead on arrival, the second worked fine until 2 weeks ago. Since then, I've had 2 more under warranty. The 3ed doesn't work at all, the present 4th, works 1 time in 4 and puts out warm water when it works.

They offered me my money back and said it is the boat.

What can I do to the boat to make it work? Any ideas?

The problem is in the valve in the lower/middle of the unit, when I operate the microswitch by hand, all is well.

/Stu


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## MacGyverRI (Nov 14, 2007)

Tankless? Try cleaning the entire heater internal liquid areas w/ plain old white vinegar. These heaters are also touchy w/ and dirt inside.

You just fill the unit w/ vinegar and let it sit for 30-60 minutes to get any calcium deposits out just like an AquaStar or Bosch unit at 6 month intervals and flush or run the unit for 2-3 minutes to clean it out. 

I had the AquaStar (bought out by Bosch) in my house and just put a 2" pipe inline (1/2" copper at ea. end adapted down) w/ a T at the top that had a 3/8" NPT plug to make it really easy to drop the vinegar in when needed.


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## jimrafford (Jan 7, 2011)

Sorry I haven't reported on the Precision temp. Have had way to much crap served up on my plate the last month. Dad had his 4th heart attack, mom had a spinal injury, our short haul turned into a bottom strip, blister repair and new barrier coat, oh, and the nuteak installation in my cockpit had to be ripped out to do over.
I have installed the heater and briefly tested it. Seems very well made. It fit in the same space as the original water heater and was pretty easy to install. It does need an external vent for exaust. Hope to launch next week and give it a thorough test.
Jim


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## WanderingStar (Nov 12, 2008)

Thanks for the update Jim. Sorry to hear of your family health problems. Wish them well. I'm also behind in my projects, having spent weeks building a new mizzen boom, and weeks trying to stop a transmission leak. 
I've got that heater on my dream list. Not sure I'll get there with kids' college debt etc. Please post an update after the season.


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