Dometic 6 Gal H.W. Design flaw while on Propane?

[Camper1]

The link directly below is a related thread from April of 2022.

https://www.winnieowners.com/forums/...en-363753.html

This Dometic hot water model (WH6GEA) will not operate on propane when at higher elevations without leaving the cover door open, period! Unfortunately, there is no adjustment on this model. Our home is at the 600' elevation and this unit always works flawlessly, as it does when camping at sea level. All internal parts are clean & bug free.

I first noticed when we were camping at 5,600'. The unit would fire, then cut out, then fire again, and cut out again. When I opened the door, it would fire & run till the water was at temperature, as it should. This has happened on two different trips.

In the older tread, there are solutions, for example removing some of the sealant around the door and propping it open while in use. Also, possibly cutting a hole in the cover door and installing something like a 2" or 3" louvered and screened apparatus over the Burner Orifice. I would rather not cut a hole in the cover door, or leave it open or propped open in inclement weather.


I also called Dometic, and I was not allowed to speak with an engineer, because I do not have a RVIA (Recreational Vehicle Industry Association) license. The front line employee could only offer me the solutions of: "The the unit was not installed correctly, or the unit does not have proper air flow". Since my 2108TB is a 2021, and works at lower elevations, I'll assume the Winnebago factory installed it correctly, so it must not have proper air flow. Well, I would agree with the Dometic front line employee and say it's an air flow problem, because the cover door is directly covering the Burner Orifice.


I guess the question is: Is this actually a Dometic design flaw, is something else going on I'm unaware of, or am I just unlucky?


Thanks!

[Ray,IN]

There is nothing wrong with your water heater. That is the laws of Physics and no engineer can circumvent them.
Yes an LP water heater can be designed to work at 5,000', but it will not work below that level.



Since the air is much less dense above 5,00' the same amount of LP requires about 3x as much air.
My Atwood WH also will not operate normally at that altitude, even though it has an air adjustment. My only solution is to leave the door open when heating with LP or heat with electricity.

[Camper1]

Thanks for the quick reply Ray.,IN!

While one cannot argue with the laws of physics, as well as what you are relaying about the need for more air to burn LP at higher elevations, I have never had this problem at the same elevations, with the previous two 5th wheels and a motorhome I've had.

Unfortunately, I cannot remember the brands/models in order to compare, it's just that this is the 1st time I've had to deal with this issue, so my thought process went to the manufacturer and their design of this particular unit.

If I can find a small enough apparatus to fit into the door, so I can keep the bugs out and to let extra air into the Burner Orifice area, I'll try that, but yes, at this time, the only solution is to leave the door open, or plug into a generator and use the electric option.

I sincerely appreciate your reply & experience and of course your service!

[wyocamper]

I live at 6,100' and regularly camp at 9,000', frequently at around 10,500', and occasionally at up to 11,000' and have never had an issue with my Atwood water heater firing up or heating water.

[Camper1]

Hi wyocamper!

I bet if you don't have snow already at your home at 6,100' it's coming soon! And that's some high altitude camping/boondocking for sure. The highest I've ever camped at once, is at about 9,000' in the Steens Mountains in Southeast OR.

Yeah, I'm not sure why RV gas/propane water heaters work as expected for some and not for others. Ray.,IN obviously has good points on the physics of burning fuel at higher altitudes, but I really feel my Dometic model is poorly engineered, with the door being so close/tight to the burner orifice, not allowing sufficient air flow, but especially with your testimony here on the operation of your Atwood!

Hopefully, like Forest River Forums do, have their (Winnebago) company reps reading forum posts, and a Winnebago representative would pass along the lack of operation of this Dometic WH6GEA model at higher altitudes, to their Dometic manufacturer representative, so we all may get 'some' clarification.

Thanks!

[Morich]

I see this as possibly just the way we now deal with things. There used to be adjustments on things like this but over time they found it very rare for folks to read up and follow the adjustments----so they stopped putting them on.
So we have to find a cure on our own or deal with it in whatever way fits us.

My choice is to look at making sure the air is the factor and not some other bogus problem we are missing. something like an overheating board when the door is closed? Sounds too strange for me to think the small amount of air needed for a water heater will not leak in around the doors and it is really easy to jump to the wrong solution.

Seems it would be reasonably simple to just drill a dozen small holes along the bottom edge of the door as a way to let more air in. If it works, then air is the factor but if not we have to move to other solutions.

In either case, I would guess that gets us a solution much quicker and with less pain than expecting anybody to agree to retrofit our water heater!

[Camper1]

I didn't think of that angle in your 1st point Morich, nicely done!

Agree with your 2nd point, and to not jump to a conclusion or solution. Part of my closing line in my original post said "Is something else going on I'm unaware of". Not sure, put with the door closed at lower altitudes, it heats up just fine, so hopefully the circuit board and other components are not overheating.

Yes, some strategically placed holes is a great idea, thanks! Probably some 1/16 or 1/8" holes would suffice and I would probably put screening behind the holes. Since we're not camping anymore this year or early next year, at higher elevations, it will be a Winter/Spring mini project. Or, just leave the door propped open a bit or full open and problem is solved.

Yeah, since my Dometic is out of warranty, I wouldn't expect any authorized retrofitting, but maybe, if anyone of authority or influence is reading, maybe something would be passed along and we would see a change for the better for future RV'ers.

[Morich]

Yes, what we often find on forums is that we throw out a bunch of ideas that might help and then it's like picking apples! We try to get the best one and try it out to see if it tastes as good as it looks!

Your mention of the board not overheating at lower does show a flaw in that idea! Any way to an easy refit of how the door is hinged to make it stand out just a crack?
Not something simple like screwed on that would allow a couple washers added to make it stand off to leave a crack?

I sure have a lot more time, now that we don't have an RV!
Kind of missing it but it's often when I think about winter coming and I need to drain the lines!

[Ray,IN]

FWIW, both Dometic and Atwood caution owners not to install bug screens due to air restriction problems.
I think I remember reading where one brand even said the warranty may be voided if bug screens are used.
Owners of both brands, please read your owners manual and warranty, then set me straight.

[Camper1]

I'm with you on multiple ideas for an issue Richard, and then one decides which one looks and works best, and then follow through to see if it is the right (or right enough) solution.

I looked at how the HW heater door attaches, and there is a seperate corner bracket on each lower corner of the main installed unit, with three screws on each corner bracket, so yes, putting some washers behind each screw would be easier & cleaner than drilling holes. We will see if this helps with the air flow problem of this particular unit the next time we're camping at higher elevations. Thanks!

With all your spare time, since you don't have a coach now, I'm sure you'll be helping lots of people out now :-)

For a unit under warranty Ray.,IN (Winnebago Master) I totally agree to assure any modifications does not void warranties. My 2021 Dometic WH6GEA model is out of warranty, but the instruction/installation manual does not say anything about bug screens, but it does state:

'Dometic Corp accepts no liability for damage in the following cases': One being 'Alterations to the product without written permission from the manufacturer' and 'Do Not modify the water heater in any way'. So, they covered themselves for sure!!

[Morich]

On the bug screen issue, I've rarely had an RV with warranty still in effect! I stopped buying new when I got tired of all the faults I got with them!
I found it worked better for me to let others work out all the bugs of the new one!

But whether to add screens or not is just one of those things that comes around to where you have had more trouble. Since I have not had any obvious trouble with furnace, frig and water heater getting air, I have gone with screens because I HAVE had trouble several times with different things getting bugs like wasps building nests !

One of the things I really don't like is finding there is a nest in there and they are really mad when I run something in to clear the nest!

[navnaz]

I had same problem with a new Dometic replacement for my Atwood. We live at 7500 and camp around 10,00’. Just wouldn’t work right, got told the same thing about wanting to talk to a Dometic engineer. I was pulling my hair out.

Brought it to a dealer, they couldn’t figure it out. My wife’s cousin, a previous RV owner, figured it out immediately. The exhaust port is partially blocked by an angled piece of metal, preventing good exhaust. We did metal-smithing and removed, reconfigured it, and turned the exhaust venting upside down, allowing hot air not to be forced down and out but up and out. It require re-mounting it with a rivet gun.

Works fantastic now. My attempts to get support from Dometic is they could care less that it doesn’t work correctly.

[The Raptor]

I had an Bug with the LPG side of my Winnebago Alpine Water Heater (worked on AC), discovered the Flame was igniting halfway inside the Tube that goes inside the Heater, it Melted the end & nearly set the plastic discharge tubing on fire that is fitted to the water Pressure release valve.
I removed the Elbow fitting that the LPG Jet is connected to, and discovered a Black Tar looking material was inside the Jet, after Cleaning the Gas flame ignited inside the Water hearer.


Although, I have noted sometimes the Pilot Flame stays on & sometimes it goes out !
Is the Pilot Flame meant to Stay on when Switched off at the Water Heater Power switch ?

[Ray,IN]

Originally Posted by The Raptor

I had an Bug with the LPG side of my Winnebago Alpine Water Heater (worked on AC), discovered the Flame was igniting halfway inside the Tube that goes inside the Heater, it Melted the end & nearly set the plastic discharge tubing on fire that is fitted to the water Pressure release valve.
I removed the Elbow fitting that the LPG Jet is connected to, and discovered a Black Tar looking material was inside the Jet, after Cleaning the Gas flame ignited inside the Water hearer.


Although, I have noted sometimes the Pilot Flame stays on & sometimes it goes out !
Is the Pilot Flame meant to Stay on when Switched off at the Water Heater Power switch ?

What brand and model is your water heater? Dometic and Atwood have not used a pilot flame for about 40 years in the states, electronic ignition only.

[The Raptor]

Originally Posted by Ray,IN

What brand and model is your water heater?
Dometic and Atwood have not used a pilot flame for about 40 years in the states, electronic ignition only.

I am thinking it is Dometic, as the Fridge & Air-conditional is.


I just tested it with the Door open, it lights up easily, but when I close the Door it gets Quieter, and when I open the Door again the Flame Burns stronger, assuming there is more Fresh Air entering the unit.

These are images, you can see the Dark area of the Tubing where the Flame was Igniting prematurely when the Jet was partially blocked;

[The Raptor]

It just finished Heating, and the Jet no longer has a Pilot light, it may be because I haven't used it that much since I purchased the beast.
So, the Gas relay switch must has re-seated itself, I hope.

I understand it has sat for two years before being sold to the previous owner, that sold it due to his wife's health issues after just a month.

Been busy fitting several JOHN GUEST Water hose fittings & a dozen hose inserts to stop all the leaks.

[Camper1]

Hey Navnanz!

I totally agree with you that Dometic does not want to be bothered with their design flaw of this particular Gas H.W. Heater model (WH6GEA). It is also odd that if dealers can't figure it out, why don't they go to bat for their customers and contact Dometic and figure this out for their customers & for all of us? I pulled some hair out too!!

It would be 'Awesome' if you have time, to post pics of your exhaust port metalsmithing modification. I can picture it, but you know what they say about pictures :-)

I may still try the mod first that Morich recommended, by adding some washers to the two lower brackets that hold the door on, to allow just a bit more air to reach the burner.

I think this is a great discussion by great RV'ers!

[Morich]

A small point that might be easy to miss is the way bugs of all sorts can seem to mess with our minds! And there are times when things just get dirty?

The orifice on this type gas is a tiny opening in the little brass fitting we can see screwed into the incoming line. That tiny opening size is critical and is actually what makes the difference in propane or natural gas items!

The size of the hole, combined with the line pressure is what helps to determine how far into the tube the gas flows. It is critical that the gas goes far enough in before firing!
You don't want it flaming out at the opening next to the orifice!

There are times when we need to assure that little hole is not getting any form of gunk in it to restrict the hole size!
A tiny blob of "bug spit" in that hole can change how the orifice feeds gas!
We don't want to go too heavy and use something hard like steel or anything harder than brass, so I use copper wire of very small gauge to make sure any deposits are broken off to blow out.
The orifice often is fairly easy to unscrew and we can try to look through the hole if our eyes are good but there are times when the easy things are the good things to try first?

[navnaz]

I will send pictures of the mod but we are heading out of town for the weekend right now, will send them when we return in a few days. FYI, I also started with the additional holes for more intake air, that didn’t seem to do much. For me it was the Dometic designed restriction of exhaust air directly through the vent.

[Ray,IN]

Originally Posted by The Raptor

I am thinking it is Dometic, as the Fridge & Air-conditional is.


I just tested it with the Door open, it lights up easily, but when I close the Door it gets Quieter, and when I open the Door again the Flame Burns stronger, assuming there is more Fresh Air entering the unit.

These are images, you can see the Dark area of the Tubing where the Flame was Igniting prematurely when the Jet was partially blocked;

The dark section of the burner tube, are you saying that is where the flame was? If so, there has to be an air leak back at the beginning of the tube; otherwise the LP mixture would be too rich to burn inside the tube.


As to being unused, my MH was parked in a barn for 8 years due to owners poor health. When I bought it, after purging the lines of air the ATwood WH started up normally.

Have you found the make/model of this WH?