Atwood Water Heater Electrical Fire

[RJKSr]

Our 30' International Serenity has an Atwood (now Dometic) GE9EXT combination gas/electric water heater. Early one morning we could smell what is best described as burning electrical components. Although it was very strong we could not locate the source. We packed up and at our next destination we still had a faint smell. We soon realized we had no hot water except via propane. A close examination under the dinette seat through the access panel determined that there were charred components in the rather small plastic electrical junction box. I switched off the 20A circuit breaker that was factory labeled water heater. When home I dug further and found that the circuit mislabeled and what qualifies for most homeowner insurance companies as a self extinguished electrical fire.

After removing the dinette seat for better access, I found 120VAC and 12VDC wiring burned and melted wire nuts and electrical tape (pics attached). I removed the damaged wiring and the 12VDC relay that is controlled by the ECO. The relay tested to be in working order. The heater element resistance tested good. I replaced the damaged wiring and made sure to use stranded 12AWG for the 120VAC leads. There was enough NM cable to cut off the damaged portion and cut back what was needed to reenter the box. After repairs, it all works. However, there was no way to close the box cover. Closer examination shows that even with 90 degree stak-ons on the relay, there is only 1/8" clearance between the relay and the 120VAC heating element connections. This leaves no way to separate the 120VAC and 12VDV wiring to only cross at 90 degrees and I could see how over time a pinched wire could short. I "extended" the cover 1/2" from the box using non-metallic Gorilla tape. Although this heater is CSA certified, the junction box does not seem to meet electrical code requirements for wire fill and allow proper separation of high and low voltage wiring. I only see a few postings about burned wiring several years ago that were chalked up to "loose connections", but have to wonder if this is a bigger problem.

Having even a minor electrical fire in a space not easily accessed is worrisome. Have others experienced this issue? Are they still using what I would term as an improper junction box? What have others done to resolve this problem? Have others found a better way to enlarge the junction box?

[AirstreamInc]

Originally Posted by RJKSr

Our 30' International Serenity has an Atwood (now Dometic) GE9EXT combination gas/electric water heater. Early one morning we could smell what is best described as burning electrical components. Although it was very strong we could not locate the source. We packed up and at our next destination we still had a faint smell. We soon realized we had no hot water except via propane. A close examination under the dinette seat through the access panel determined that there were charred components in the rather small plastic electrical junction box. I switched off the 20A circuit breaker that was factory labeled water heater. When home I dug further and found that the circuit mislabeled and what qualifies for most homeowner insurance companies as a self extinguished electrical fire.

After removing the dinette seat for better access, I found 120VAC and 12VDC wiring burned and melted wire nuts and electrical tape (pics attached). I removed the damaged wiring and the 12VDC relay that is controlled by the ECO. The relay tested to be in working order. The heater element resistance tested good. I replaced the damaged wiring and made sure to use stranded 12AWG for the 120VAC leads. There was enough NM cable to cut off the damaged portion and cut back what was needed to reenter the box. After repairs, it all works. However, there was no way to close the box cover. Closer examination shows that even with 90 degree stak-ons on the relay, there is only 1/8" clearance between the relay and the 120VAC heating element connections. This leaves no way to separate the 120VAC and 12VDV wiring to only cross at 90 degrees and I could see how over time a pinched wire could short. I "extended" the cover 1/2" from the box using non-metallic Gorilla tape. Although this heater is CSA certified, the junction box does not seem to meet electrical code requirements for wire fill and allow proper separation of high and low voltage wiring. I only see a few postings about burned wiring several years ago that were chalked up to "loose connections", but have to wonder if this is a bigger problem.

Having even a minor electrical fire in a space not easily accessed is worrisome. Have others experienced this issue? Are they still using what I would term as an improper junction box? What have others done to resolve this problem? Have others found a better way to enlarge the junction box?

Hi RJKSr,*

Please send us a direct message with your contact information, email and the last 6 digits of your VIN so we can learn more and share it with our Customer Service and Technical Support team. We look forward to helping you get this resolved.

Thank you.

[chris_souder]

2015 Flying Cloud 25, Atwood GE-9 EXT water heater failure.

Last week we had the water heater stop working with gas and burning plastic smell when electric turned on. Your post helped find the electric problem in the junction box of the AC and 12v relay(Photo attached).
In my case an AC spade connector on the relay was broken and shorting AC and burning the plastic. I believe the spade connection was damaged on install from cramming all the AC romex and wire nuts against the spade connector on the relay which caused it to break.

What's strange and concerning is that no fuse of circuit breaker was tripped, leading to smoke from the short and possible fire if not turned off due to smell. Very bad if sleeping just above the water heater as in our case.

Waiting on new relay and then see if the gas works or then figure out what is failing on the gas side. Anyone have ideas on if the shorted relay could cause the gas side to stop working? Will update when relay installed.

Thanks,
Dan Souder
Relay part #: Zettler AZ2280-1A-12D

[RJKSr]

Glad you found the problem. You indicated the water heater also stopped working on gas? Hope the short did not feed back to your water heater control board. In my case the breaker also failed to trip, but the gas side worked. Likely because the low voltage wires were melted in half. Took my unit in for service at Jackson center & had them check out the water heater to be sure it was safe. They gave the OK but also could not get the j-box cover w/the relay to close properly and tightly electrical taped it partially closed. That is similar to how I found it the first time. I re-worked using gorilla tape so that the cover is 1/4” away to avoid pinching wires against the relay & heating element terminals. In my opinion this is an Atwood/Dometic design failure as there is no way to properly maintain low & high voltage separation. The junction box needs to be at least 1/4” deeper and the relay positioned further to the side of the heater element terminals. Hope your repair goes smoothly.

[Janssvt]

We had something similar a couple years ago, smelled hot wires. Took the cover off in the bedroom area to get at the water heater and it had burned wires where the box had rubbed the wires against the wall. It was so packed in that my husband had to cut a piece of the wall out to get it out. Unfortunately, it started to smell again so we didn't use it on electric and the other day it didn't work at all on electric. Taking it for new refrigerator Monday so will have them check it out.

[GMFL]

This happens quite often with the relay. Loose wires = heat.

[chris_souder]

I have found the problem with the gas side. Probably did not need to buy Dino PCB, but oh well.
The problem was that the board was not getting 12VDC on orange wire when the gas switch was turned on. Checked fuses and the switch connection all good. Turns out it was a bad connection in the connector that connects the wires from the switch. Pushed the orange wire into the connector firmly and problem solved. Goes to show failure can be something as simple as failed connection.
So always check voltages and connections before going out and replacing PCB. Much cheaper.

[Al and Missy]

If what you had is like the picture GMFL shared, that is not a short, but a bad, arcing, connection. The increased resistance creates heat, but may well not draw enough current to trip the breaker. Confined to a small area, it doesn't take much power (just a few watts) to generate a lot of heat and melt the plastic. If the broken connector had worked loose and contacted a ground or neutral wire, that would be a short and should trip the breaker. Still bad on whoever did the install or repair.