propane on demand hot water heaters (no electricity)

I bought my first on-demand propane water heater in 1986.
A small Paloma PH-5, sold as a boat water heater, propane with no electricity required.
It worked great. The water temperature was controlled by restriction; if you needed hotter water, you got less, but it sure was hot.
It had a standing pilot light and used water flow to ignite the burner.
Having lived without running water and heating water on top of a stove, this little heater was awesome!

After a couple of years, and no longer a single guy, I decided to upgrade to a larger unit.
I purchased a Paloma PH-12.
Similar to the PH-5 in that it used no electricity, had a standing pilot light, and water flow ignited the burner.
The largest difference was that water temperature was controlled by flame intensity, more water flow produced a larger gas flow heating your water to the desired temperature.

Thirty-five years later that same PH-12 is still on the wall and providing our hot water.
Unfortunately, she is on her last leg, a pinhole leak developed at the heater core.
Brazing/ soldering might be a possibility but would require removal from the wall and a complete disassembly.
Even then, the other solder joints are so close that the chance of creating a new leak or three is too high.
I attempted to Band-Aid it with JB-weld, This reduced the leak from spraying the wall to a steady drip if the water is turned on.
With a towel and bucket, I can catch those drips, but now we only turn on the water for showers and dishes and then turn it back off,
The search for a replacement began...

In the last few weeks, I have learned quite a bit about the "new" on-demand water heaters.
Over 15 years ago my brother purchased a "Bosh" on-demand heater.
To put it nicely I Was Not Impressed!  
To start it requires electricity at all times, power outage... no hot water! That alone is a deal breaker in my book.
Requires special exhaust pipe, good old double wall is no longer good enough...
There is a fan that turns on whenever it wants to, even when the water is not running.
Yes, it heats the water but what a technological disaster waiting to happen.
At the time, I thought only the "high-end" heaters were like this and I foolishly assumed that there were still plenty of "normal" heaters like mine...

Oh how wrong I was!
In 2024 almost all on-demand heaters are digital and require power and special venting.
There are way too small, low-output heaters listed as outdoor only, although many of them also require electricity to operate.
I spent hours and hours searching online.
My beloved Paloma had been discontinued long ago (who knew?)  any old stock items were gone, and repair parts were all discontinued.

After hours of searching, I finally located a website that listed "Legacy" Paloma heaters!!! They listed PH-12s!!!  Oh My what luck!
I attempted to complete an order, but it appeared the website was not working.
I pick up the phone to call them, Liz looks at me like I'm crazy and says "It's 7 pm on a Sunday"
I call anyway and much to our surprise I get an answer!  A real person no less!

Steve is a great guy, fun to talk to, and chock full of information that I desperately needed.
I tell him I want a PH-12... while laughing he says OH YEAH we got so many, that I'm tripping over them to get to the phone...
Then he says, you know that there are no Palomas or parts left... but I can help you with what you need.
I have been selling on-demand water heaters for over twenty years now.  The Palomas were ideal water heaters but unfortunately, the building codes forced the manufacturers to move away from a simple heater that lasts 37 years to an electric control marvel that is sure to break down in a few years.
He does not recommend on-demand at all anymore and does not use one in his house.

He said in your case, there is only one make and model machine currently available that will check every box that you want checked.
I sell this machine to 99 out of 100 former Paloma PH-12 owners!
A Marey 16L  
Of course, no 110vt power is required.
There is no pilot light and power for ignition is provided by two D cell batteries.
It has an output of almost 20,000 BTU's  higher
It is certified for indoor installation.
It mounts on the wall where the Paloma was and uses the same 5" double wall  I already have!
Here is a link    https://marey.com/product/power-gas-16l-lpg-dp-ga16lpdp/

"Mary" was shipped a few days ago from Florida, she was in Kentucky last night and is expected to arrive here on Monday.
I'll be sad to see the Paloma go it sure was a good investment!
I'll offer her on eBay as a working parts machine, and perhaps someone will be excited to find her.
I have high hopes for Mary, and after chatting with Steve it sounds like my best (and only) choice.


























     





 

Nice! It's a pleasant reminder that good people and good gear are still out there, and it's still possible to dodge the planned obsolescence crapola.

Thomas -

I just forwarded the link to my son, who is contemplating whether to buy a used cargo van to outfit, or to buy some land and put up a tiny house.

Thanks for passing it on to us.

When our water heater finally died about a year and a half ago (Montgomery Wards badged, it started leaking, and I knew its time had come; the aluminum data plate said it was made in 1961!), I found the most efficient tank water heater I could get that didn't need to be grid connected, for all of the reasons you mentioned.  My brother has one that uses a power venter for the exhaust, and let's just say that it hasn't been problem-free.  Probably no worse than any other modern appliance, but that isn't exactly a ringing endorsement!  None of the tankless models I found seemed dumb and basic enough for my liking (but I guess I hadn't discovered the Marey).

I found a Reliance which runs all of the electronic controls off a thermopile heated by the pilot.  It is efficient enough that we got a rebate from the gas company ($100, but it beats a sharp stick in the eye), and it had a 10 year warranty.  The gas company now send us various "stuff" every year I guess because we're now in their good books, or something).  This year, it was a shower head and hose, several flow restrictors, hand sanitizer, lib balm and other sundries.  The best price on the model of water heater I wanted, even without considering shipping, was to order it from my local hardware store.  I placed the order on a Monday, it came (at no additional freight charge!) on the scheduled weekly delivery truck on Thursday along with all the other stuff they'd ordered that week, and by the end of the day on Saturday, I had installed it, having replaced a bunch of crusty and suspect pipe and added a couple of 1/4 turn ball valves to replace old gate valves in need of an overhaul.  The valves went in my bucket of plumbing stuff, to be cleaned up and have the washers and stem packing replaced at a later date.  All up, just over $1000 in parts and materials.  It's a 50 gallon tank (the old one was a 30 gallon, though we never had any trouble with running out of hot water, even when we had 6 girls from a traveling youth choir stay at our house).  50 gallons is probably overkill, even if we end up with a whole pile of house guests for Christmas, but that's just how it came.

Had I known about Marey, we might have ended up with the NG version, instead.

I have an on demand in my barn.  It is ignited by D batteries that seem to last forever. It is hooked up to a 20 lb LP tank….that also seems to last forever.  It provides hot water to wash my hands or for a quick shower when I am too filthy to step into the house. The tank is hooked up by hose to a freezeless hydrant.   The hose has a port to allow the hose to be drained.

John F Dean wrote:I have an on demand in my barn.  It is ignited by D batteries that seem to last forever. It is hooked up to a 20 lb LP tank….that also seems to last forever.  It provides hot water to wash my hands or for a quick shower when I am too filthy to step into the house. The tank is hooked up by hose to a freezeless hydrant.   The hose has a port to allow the hose to be drained.

Good job. IMO that is how you do that.

John F Dean wrote:I have an on demand in my barn.  It is ignited by D batteries that seem to last forever. It is hooked up to a 20 lb LP tank….that also seems to last forever.  It provides hot water to wash my hands or for a quick shower when I am too filthy to step into the house. The tank is hooked up by hose to a freezeless hydrant.   The hose has a port to allow the hose to be drained.

Exactly same setup here in my little bath house - I also unscrew the tank plug and the showerhead hose after each use in the winter. I bought literally the cheapest one I could find  in an actual store (I don't do online ordering) Ecotemp L5 I think it is?

Question: Compared to a gas cooking range (which is probably also not vented), how much exhaust does an on demand water heater emit?   While my on demand is in my barn and only intermittently used so venting is not a concern of mine, I find myself wondering about the need to vent an on demand water heater that uses an electronic ignition in a home.   How many minutes a day would such a heater be actually in use? I suppose I would have to begin by also questioning the size of the home, how tight it was, and how many family members, etc.   I suspect a single kerosene lamp, burning for 3 hours each day, would give off far more exhaust.

Good question John;
I would say that the output is similar between a gas oven and a water heater.
But, even with just the two of us, between showers, dishes, laundry, and hand washing, the water heater is in use much more than the oven.
In the oven, that heat is diffused.
The on-demand water heater releases a large volume of concentrated heat, more so than an oven, an unvented propane wall heater, or my propane refrigerator does.
I do not think I would want that heat released indoors, the fire hazard is a given, but during the summer, no one would want that extra heat.
Quite a few people build an outdoor kitchen to avoid heating the house.

I would say in a home, a propane water heater does need proper venting.

You may find parts at one of the few ship's chandlery's that still exist.

Well, Mary arrived on Tuesday.
Well packaged and in good condition.

Yesterday afternoon after several trips to the hardware store, I got to try her out for the first time.
I was suitably impressed!
I did have water leaks(drips) at my lines but after working all day I opted to place a catch pan underneath and take a shower.
After my shower, I turned off the water to the heater so it did not drip all night.


Today, I went in to see about stopping the drips.
Good grief!  What a pain in the butt!
I decided to make my cold water flex connection much shorter to match the 12" flex on the hot side.
A trip to the hardware store and I was all set... until I needed to return some of what I bought and purchase other different parts...
Then I assembled all the pieces using proper pipe dope (thread compound) I thought everything was tight... but think again...
It only leaked on the cold water side, the hot side was fine, but it leaked at every new piece I had installed!!!
I should mention that we have gravity water, when measured outside at the freeze-less hydrant in the yard water pressure is 125 psi...
A bit higher than the average home which is 40-50 psi.
Mary however works from 8psi up to 145psi so all good.
As a side note, Mary is not recommended for use at more than 2000' elevation.
I'm at 2600', but when I chatted with Steve he said I was still OK..
So, I went online and asked Google, and I learned something new!
There are two common ways to seal iron pipe.  
You can use Teflon tape or you can use pipe dope.
Both are highly recommended and both failed me!  Dam I hate when this happens!
I ended up at a plumbing website, where I learned that for pesky high-pressure leaks, it is ok to use Teflon tape and pipe dope at the same time!  
Who Knew? I took off all that I had done, I carefully taped and doped each piece.
I brought as many as I could to the shop and used the vice to make sure every fitting was as tight as could be.
I used large pipe wrenches on the fittings that had to be installed in place.
That did the trick! when I turned on the water I had no drips!

Mary is quite the machine! She ignites instantly when you turn on the water.
If you slow down the flow at the tap, she is capable of producing scalding hot water.
There is a neat LCD meter that shows the outgoing water temperature, it was showing 158F at the kitchen tap with the water slowed down.
Opening the sink all the way lowered it to 120F.  

We will need to try different adjustments, to fine-tune for the correct temps.

I am sorry to see Paloma retire but I am very pleased with Mary taking her place.
The owner's manual sucks, but the installation is straightforward enough that you really do not need it.
They claim to have great customer service and encourage you to call.

At just over $400, a good buy for what appears to be a quality built heater.








 

Thanks for sharing this info, I am intrigued.

I am also wondering at the tankless electric heaters available in the US. I used to live in Germany, and everyone had a few electric tankless water heaters in their home, one in the kitchen, one in each bathroom. Why can we not get the same quality appliances in the US?

I am frustrated because it seems so wasteful to have that tank of hot water in my basement, constantly heating. I don't need hot water 24/7. I wanted to install a tankless, but apparently my electrical panel won't handle it, I'd have to get an upgrade. Something seems off about this situation.

The Marey is now out of stock. They must have had a rush of permies purchasing all they had!

Suzanne Jabs wrote:I am also wondering at the tankless electric heaters available in the US. I used to live in Germany, and everyone had a few electric tankless water heaters in their home, one in the kitchen, one in each bathroom. Why can we not get the same quality appliances in the US?

Seriously. I think it's the standard outside North America (it's certainly ubiquitous in Japan and here in Brazil). The idea of heating a tank of water, and keeping it warm, even in an apartment, seems ridiculous to me.

Yesterday, I listed Paloma as a nonworking fixer upper on eBay, I also listed it on numerous local groups and Facebook marketplace.
I expected her to sell "locally" someplace that's within 100 miles or so.
This morning She sold on eBay!!!
Paloma is moving to Colorado!

I'm so glad she is going to continue working!
Hooray for a free marketplace!

Meanwhile, Mary has made herself right at home, a fine replacement for Paloma!    

I'm interested in knowing what kind of venting you used...I don't see anything in the photos but they cut off the top where I assume the vent it.  And have you noticed any fumes when you are next to the water heater and it's running?      

Hi John;
Marey uses a standard 5" double wall propane pipe.
I used metal duct tape at the joint to confirm it was sealed.
There is no smell at all.
The same design pipe was used on all water heaters until the advent of the "Direct Vent," which supplied fresh air and vented the exhaust through the same pipe.
We are still learning where to set Mary's dials.
She is capable of producing extremely hot water (180F) if you set it wrong.
Our preferred temperature for showers is 115-118F, but for washing dishes, a temperature in the 90s is preferable.
Very nice, there is an LED temperature gauge easily visible from across the room

I'm excited to run across this thread because I'm not a plumbing expert in the least and, when I build my house, I wanted to know what the best water heater was.  From my research, plumbers seem to recommend tankless water heaters more often over tanks.  But, which one?  I want propane but I don't want ANY "smart" gadgets.  Heck, I don't even like digital displays.  I like basic, with manual knobs, levers, and switches.  (Imagine my disappointment when looking for a new vehicle after not having one for 24 years.  Washers and Dryers, too.)

The house I plan to build will be about 1,500 sq ft, 2BR, maybe 2 BA, single story but with a basement.  It'll be on the grid, though very rural.  But I want it to function fully as an off-grid house, too if it needs to.  

Do you think this would be a good choice of water heater for me?

Hi Emmet;
Yes, the Marey is entirely self-reliant.
No power is needed other than two D-cell batteries for instant ignition.
95% of all the newer on-demand water heaters require electricity to work and have vent fans that randomly turn on night and day.
When your hot water needs are low, an on-demand heater is very efficient. (Why heat water until you need it?)
When there are more people trying to use hot water, suddenly, a tank heater becomes more efficient.

Just an awesome thread for both home and farm use of a tankless hot water heater!..... Great ideas here.

Thomas, have you found a way to control or set the output water temperature you prefer?  Is it easy to do this, or do you have to fiddle with it each time?  

Hi John;
For now, we have settled with changing the summer/winter switch and leaving the other settings alone.
For showers and laundry, we use the winter setting (full burners)
For the kitchen sink, we use the summer setting (one less burner)
Our water temperatures remain the same in summer or winter.

We watch the digital output when setting shower temperatures.
For some reason, this heater does not play well when mixing in cold water.
It can get scaldingly hot.
So we run the shower on hot water and do not mix it.
Showers are perfect from 110- 118F. If it starts getting hotter, we increase the flow at the showerhead, and the temperature lowers back down.
Dishes or hand washing are best done at 90-95F; if it is not hot enough, we slow the flow, and it heats up.

The Marey is quite different to operate than the Paloma was, but we like it.

Thomas, my Rinnia unit has no batteries and the spark is created by a water wheel when needed.
I dont use galvanised water fittings because they clog up over time with corrosion.
In Australia the flexible water hoses used to hook up just about any internal water using machine, are breaking and costing $A40 Million in insurance claims.
They last between 5-20 years.
I found a USA made range from Falcon, made entirely from Stainless Steel and will not break.
I suggest a look.

Two mornings ago, when I got up, Mary did not heat the water???
The digital temp gauge lit up, and water flowed, but no flame?
Luckily, I do not need hot water to make coffee! I tried it several times, took my coffee and went to Permies.
I tried again a couple of hours later, and it worked just like usual.
Hmmm
It worked flawlessly for the rest of the day, with regular on and off use.
Yesterday, I went to get hot water for my coffee. There was no flame, and after a few hours, there was still no flame.

Mary uses two 'D" cell batteries.  I suspected they might be the problem.
A search produced one new "D" cell, which I installed, hoping one new battery might be enough.
Success, Mary lit off right away!
I ordered Batteries and hoped for the best. So much for hoping. She worked about half the day and then quit. (Adding just one battery is doomed to fail!)
I made a trip to our local store, where I acquired two new batteries.
With new batteries, Mary is now working like she is supposed to.

So, it seems that Mary's batteries will last just over three months with daily use (unlike John's).
I ordered an eight-pack to keep on hand, so we will not run out again!

If you purchase your own Mary, I suggest purchasing a stash of "D" cells simultaneously.

Hi Thomas,  thanks for the post regarding how long batteries last.   As I have commented elsewhere, I have a h2O water heater in my barn. I suspect it has had the same batteries that I first put in it several years ago. That is not a statement as to how great my batteries are … rather it is about how little I use it.   I will make a point of stockpiling a few batteries just in case I need to put it to serious use.