Close call (fire) with water heater

[Scotty092278]

Back from the mountains after a short trip with the family in which we had a bit of a scare the first evening.

Pulled into camp with our 2016 Keystone and turned on the propane side of the Atwood 6 gallon gas/electric water heater (model GC6AA-10E). In hindsight, it immediately it had an unusual odor. Within about 20 minutes, the flip-down door had black char covering the exhaust grate and there was a dark tint to the trailer paint just above. The pressure relief valve was dripping, too, which it usually does not do. Upon seeing all of this, I flipped the gas switch off and we left it off the rest of the trip.

I initially thought I’d heated an empty tank, but it still had water from the previous weekend’s trip. Plus, the valve was dripping and a normal stream of water shot out when I pulled the valve handle. Then I wondered if it was just something like a wasp’s nest that was burning. That, to me, though, doesn’t explain the water inside heating to the point that it caused the valve to drip.

Any suggestions as to what might have happened?

We’ve got some good RV shops in town, but they’re incredibly expensive. If it’s something I can test and potentially fix myself, I would like to explore that route first.

Thanks!

[loggenrock]

CloudDriver - like your mod for emptying the HWH!

[opnspaces]

Glad to hear it was just soot from the incomplete combustion and not an actual fire as that would ruin a vacation pretty quickly. I've had a similar issue once but as you and others noticed I heard the weird burner and shut it off before it made a big mess.

As far as the leaking pressure valve, that can happen if you lose the air pocket at the top of the water heater tank. The fix is easy but probably best performed with the water heater cold.

From Atwood



From Suburban

[naturist]

Having found my water heater burner tube clogged with dead stink bugs the first time I tried to fire it up a couple years ago, it is now Official Standard Operating Procedure™ here to clean out the burner tubes for both furnace and water heater each spring and after every time of storage over a month or so.

Yeah, I found out the same way the OP did, when the heater roared oddly, and a walk around the side showed black soot and other ugliness on the side of the trailer.

[Scotty092278]

Thanks, everyone. I appreciate the great counsel. I lit it again to observe it, watched a lazy orange flame take off, and smelled that same odd smell.

I then took the air compressor to it and blew out what only turned out to be a little bit of debris. However, it is now producing a much cleaner, blue flame with that familiar hot water heater sound.

Thanks again. I’ll chalk this one up as a learning experience and add blowing out the burner tube to the regular RV to-do list.

[DFord]

It's very easy to run a rope through the burner tube after removing the burning assembly and tying a rag in the middle of the rope. Then pull it back and forth through the burner tube. Repeat using another rag until the rag comes out clean. The tube will then be clean. Examine the burner assembly and make sure it's clean and free of rust and webs.
The orifice of the burner is small but not so small spiders can't get inside it to block it with their web. Make sure there's no web blocking it. If necessary, unscrew it and clean it but be sure you don't damage the opening in anyway. The sound of the burner when the correct setting of the air shutter should not be a roar but just short of it. Make sure there is no yellow in the flame - dust will cause an red/orange flame even if the air shutter is set correctly. The fumes from water heater should NOT have a sweet smell to them - that would be a sign of incomplete combustion. They shouldn't smell at all.

[CloudDriver]

I had a similar issue with our older model Atwood water heater several years back. I was doing pre-trip testing and when I turned on the water heater flames came out of the air slots in the burner. Immediately shut it down and later found a spider web right at the elbow of the burner tube. Cleaned it out and all good to go.

[Retired_JSO]

Sooting from the chimney vent area is usually a sign a spider or other insect has taken up residence in the burn tube cutting the air supply needed to burn clean.

[rk911]

we had a similar fire in our Atwood 10g WH a few years back. source was traced to a spider's web in the air tube. i check it regularly now. btw, our RV insurance covered the entire repair less deductible.