Water heater issues

I found this forum on searching for help with my Dometic WH-6GEA water heater (installed in a new 2021 2108TB Winnebago trailer, purchased FEb. 2021 and used a few times since). First I'll confirm that replacing that thermal fuse was also necessary here to get my unit going again. I had spares on hand due to warnings on another forum about this general issue on Dometic water heaters (not specific to this model). I also replaced the circuit board with a USA-made "Dinosaur Board" Model UIB64 as that was recommended as point of failure by folks on another (Facebook) forum. My issue is that when running on propane the burner will go off and on before the water is heated, at irregular intervals. Sometimes burns for 30 sec. then off, sometimes for a few minutes then off. Then it'll kick on again after a short period. Or I can start it again by clicking it off/on. Very sporadic. This has happened at various elevations from 5000 feet down to 1000 feet (I don't think that is a factor) at air temps in the 60s. Meanwhile when burning, the flame ebbs and flows (or the noise does anyway) sometimes "roaring" which is when I believe the thermal fuse may have finally been melted at one point. When you open the access door to observe the flame you cause the flame to roar more so you're not really seeing the status when the door is closed except by sound. It worked fine at checkout with the RV dealer (of course). I live far from the dealer and will be doing repairs myself. It almost seems like it's getting too much air but there is no "air shutter" adjustment as I saw in some YouTube videos for this model. It's apparently too new a model to have accumulated much information and fixes from users. The manual is not much help. The only thing I have not troubleshot so far is the gas pressure at the water heater. But my stove burners and fridge work perfectly on gas. Thanks for any suggestions. In order to possibly help someone else, I'll attempt post photos of the thermal fuse and its location, of the original factory board as I unplugged it (pretty easy to do), of the installed Dinosaur board (I had to modify the cover to route wires, cut a hole in bottom of the cover with knife or clippers if your heater is configured like mine) and what my burner looks like in operation (with door open of course). Seems like it has a lot of orange in the flame, but again, this is with door open. Edit: I couldn't post photos within the forum but here's a link to my website page with the photos I mentioned.***Link Removed***
Edit again: I'm sorry I couldn't figure out how to share photos here. Upload did not work, and my link was removed as soon as I posted it. Possibly because I'm a new member. Hope the info is helpful to someone anyway.
(And editing again, 6/15/21:) I went camping for 2 days and the water heater worked fine on gas (using 12V power only in the camper), it burned through 2 heating cycles without an issue. I'm thinking it's a bad connection somewhere but I haven't found anything obvious. At least 4-5 other people with the same water heater on a Facebook Winnebago forum (Winnebago Micro Minnie forum) are also reporting similar issues...

sandmanj wrote:
So I'm very grateful for this posting I've been trying to solve the same issue and kept looking past the thermofuse!

Disconnect the thermal fuse and clean the contacts. I periodically have to do this to get it to work.

So I'm very grateful for this posting I've been trying to solve the same issue and kept looking past the thermofuse!

dougrainer wrote:
1. If you have 12 volts on the Brown AND NEG(GROUND) at the Green the board is bad
2. WHERE did you get your replacement Board? The reason I ask is, Atwood(Dometic) had hundreds of thousands of BAD boards a few years ago and they pulled ALL replacement boards from suppliers and replaced the Boards on all WH stock. DEALERS(Service Centers) if they had any sense(a lot don't) could send in their bad replacement boards and Dometic would replace them. But, since some business's are not honest, or just stupid, they would then sell those bad boards or someone on the Internet got hold of those bad boards and would sell them on the Internet. Because of this I would advise ANYBODY to not buy Dometic WH control boards off the Internet for a few more years. These BAD Boards did work but would fail after a few days/months. Some did fail at first operation. There is now way for Dometic to track the BAD boards. There is NO way for you or anybody to determine good new boards from the bad boards. It would appear you got a bad replacement board. Doug

Hi, sadly I did order the second board from the internet (E-BAY). when I first jumped the thermal fuse all I got was a buzzing sound. I put the original board back in and it fired right up. Thank you.

Old-Biscuit wrote:
That WH-G6EA is a brand new revision...Dometic FINALLY moved the electric element/DC Relay from backside to Front of WH Tank....YEAH
WH...(Product ID_
G ...(GAS)
6 ...(Volume)
E ...(Electric)
A ...(Revision)

Combustion/Exhaust 'U' Tube is now Stacked vs the Diagonal on previous version (to make room for DC Relay/Element
DC Relay/Element is under that cover on right bottom area in outside compartment



Wiring scheme is same as a GC6A-10E/GC10A-4E versions (from 2004--present)

So you verified that you have 12VDC from On/Off Switches to circuit board
Orange wire....Gas
White wire ....Electric

You verified you have 12VDC on Brown wire from circuit board to/thru thermal fuse, to/thru T-stat and back to circuit board via Brown wire

Did you remove that 2A fuse and verify it has continuity?
Second Board not working either

Thermal Fuse (in clear tube) if blown will stop ALL DC back to circuit board
Remove it and jumper Brown wire straight to T-stat

2A fuse protects the circuit board
So if blown then there is a short in circuit board
2 Boards...doubtful

Check ALL the ground connections Pin 6 & 5

Hi, thank you for all the info. You win the prize. I jumped that thermal fuse and it fired right up. Thank you all for your support in figuring this out.

1. If you have 12 volts on the Brown AND NEG(GROUND) at the Green the board is bad
2. WHERE did you get your replacement Board? The reason I ask is, Atwood(Dometic) had hundreds of thousands of BAD boards a few years ago and they pulled ALL replacement boards from suppliers and replaced the Boards on all WH stock. DEALERS(Service Centers) if they had any sense(a lot don't) could send in their bad replacement boards and Dometic would replace them. But, since some business's are not honest, or just stupid, they would then sell those bad boards or someone on the Internet got hold of those bad boards and would sell them on the Internet. Because of this I would advise ANYBODY to not buy Dometic WH control boards off the Internet for a few more years. These BAD Boards did work but would fail after a few days/months. Some did fail at first operation. There is now way for Dometic to track the BAD boards. There is NO way for you or anybody to determine good new boards from the bad boards. It would appear you got a bad replacement board. Doug

It's always good to know if the part you are replacing is bad before you replace it. 1st, do you has a good gas supply? Do you have 12 volt control voltage? Did you try the 120 volt element?

That WH-G6EA is a brand new revision...Dometic FINALLY moved the electric element/DC Relay from backside to Front of WH Tank....YEAH
WH...(Product ID_
G ...(GAS)
6 ...(Volume)
E ...(Electric)
A ...(Revision)

Combustion/Exhaust 'U' Tube is now Stacked vs the Diagonal on previous version (to make room for DC Relay/Element
DC Relay/Element is under that cover on right bottom area in outside compartment



Wiring scheme is same as a GC6A-10E/GC10A-4E versions (from 2004--present)

So you verified that you have 12VDC from On/Off Switches to circuit board
Orange wire....Gas
White wire ....Electric

You verified you have 12VDC on Brown wire from circuit board to/thru thermal fuse, to/thru T-stat and back to circuit board via Brown wire

Did you remove that 2A fuse and verify it has continuity?
Second Board not working either

Thermal Fuse (in clear tube) if blown will stop ALL DC back to circuit board
Remove it and jumper Brown wire straight to T-stat

2A fuse protects the circuit board
So if blown then there is a short in circuit board
2 Boards...doubtful

Check ALL the ground connections Pin 6 & 5

My expertise only runs to wiggling it or hitting it with a bigger hammer!

One of our actual techs should be along to save the day soon :)

BFL13 wrote:
I only have an old WH but it does have the board with a 2 amp fuse. I think you are saying you by-passed the big plug with the pos wires that goes into the circuit board, and went to the fuse and then it all worked.

It can happen that plug, if it slides onto the edge of the board, loses good contact. Cure is to pull it off, clean off the contact part on the board and anything in the plug contacts and put it back on. Wiggle it some, see if that gets you contact again.

HI, I tried to wiggle them around thinking it might be a loose connection but didn't work. Thank you.