Water Heater Go Boom

[Timex]

The last couple of trips we have been experiencing an intermittent situation that has been happening to our Suburban water heater when it is lighting. This doesn't happen every time but only 2-3 times on a week long trip. I flip the switch on the control panel for the water heater to light on gas. Let me go back here and say that during the summer months I use the fridge and water heater on gas and let the AC have all the amps it wants. With a tv, lights, fans and such I doubt I rarely hit 25 amps but just want to be on the safe side. Now back to the story; on flipping the switch and just after the burner lights, there is, for lack of a better word, an explosion in the burner chamber of the water heater. The burner usually lights fine and heats the water good. It's the explosion and an extra "smell" of gas that is concerning. Attached is some pics I took today with the shield or exhaust deflector(whatever it's called) already taken off. Inside the burner tube is a good bit of corrosion. Is this normal? The flame is the orange/blue color that is what is expected. I can never be outside and catch it doing this. It never does it while I'm standing there watching it so I can't say for sure that it is happening in the burner tube or where the gas comes out of the manifold. I plan on using a shop vac and clean as much of the rust up I can get to. Is there some kind of brush that I can run thru the brass tube to clean out dust or possibly a spider web that could be partially blocking the gas flow to the igniter? The BOSS said that I will get this problem corrected before the next trip.

So what advice does the congregation have to offer? I really don't want it to sit at the dealer for 2 months and them to say I need a new heater.

[wmtire]

The actual tube (pic #1 above) may be partially clogged and not allowing a proper air/fuel mixture. This is a known problem area for spider webs, dirt dobber nests, and soot in general. Some people have had success blowing some compressed air thru it, to blow out problems... while others have had to remove the tube itself to get the problem cleared out (which also isn't hard to do)

They also make a flexible brush designed for this cleaning purpose that you can use.

https://www.makariosrv.com/water-hea...cleaner-09103/

[Timex]

Thanks for the reply. I figured I could probably take the tube off and clean it thoroughly but I didn't want to mess with the adjustments that might have to be made once I take it off. I thought about making a little homemade brush with a coat hanger with a piece of cloth tied to it and run it back and forth through there. Is there anything in the tube that could be messed up if I pushed something through there?

[5picker]

Originally Posted by Timex

Thanks for the reply. I figured I could probably take the tube off and clean it thoroughly but I didn't want to mess with the adjustments that might have to be made once I take it off. I thought about making a little homemade brush with a coat hanger with a piece of cloth tied to it and run it back and forth through there. Is there anything in the tube that could be messed up if I pushed something through there?

Shouldn't hurt a thing.
They actually make a cleaning brush to be used to push through there similar to a gun cleaning brush.

[Timex]

I looked up the link that Bobby posted earlier but that link said it was unavailable at the time. I now have found some flu brushes on Amazon that will probably work as well. I'll get them ordered and then try it out with the Shop-Vac. I'll also after I get everything cleaned up will use the soapy water test to see if there might be some leaks in the gas line. Is the corrosion and the burner chamber a usual occurrence?

[5picker]

Originally Posted by Timex

I looked up the link that Bobby posted earlier but that link said it was unavailable at the time. I now have found some flu brushes on Amazon that will probably work as well. I'll get them ordered and then try it out with the Shop-Vac. I'll also after I get everything cleaned up will use the soapy water test to see if there might be some leaks in the gas line. Is the corrosion and the burner chamber a usual occurrence?

Looks similar to all the water heaters I've seen.

[Jeff_and_Abby]

X2 on what WMTIRE and 5PICKER said ...

Be careful with the cleaning, obviously don't want to pierce the flue tube, but it is metal and God only knows what has tried to build a home in there.

Shop-vac is a great way to get stuff out.

The Atwood on our previous TC looked like hell at 21-years old, and still worked like a champ. The inside of the flue was downright ugly, plenty of rust on the exhaust and enough corrosion on the gas side and regulator/valve.

Don't know that we would call it an explosion, but there were lighting episodes where there was a sufficient "Pop" obviously caused by gas build-up in the flue between valve opening and ignition.

"Generally" Propane has this deliberately limited fuel-air range that is combustible, point being that it is pretty darn safe.

If you get the loose stuff outta the gas venturi and the flue, and it burns with a mostly blue flame, you are good to go.

[Timex]

When I call an explosion sounds almost like someone is on the outside of the trailer and they hit it with something. Sometimes it doesn't light immediately and has to go through a cycle. The last time it happened my wife was in the shower and it apparently was going to light and run again and that's when the explosion happened again. I smelled gas and the fault light was on. Immediately turn the switch off and opened a vent to get the smell out. I'll do some cleanup and take more pictures and run the system again to see how things work. I'll post results after that.

[ard58]

Had an older 5er years ago that when the water heater lit would actually shoot a flame out the side of the trailer about 8-10", along with the explosion sound. It was scary. TT dealer, ended up after taking it there 3 times, replacing the gas valve itself. Hope yours works after the cleaning.

[RamblerGuy]

I had explosions like that. The ignitor wasn't firing the gas every time. Sometimes it would fire after a few tries when there was gas in the flue, and it would ignite with a pop. Adjusting the ignitor electrodes fixed it.

If cleaning it doesn't cure the problem, try adjusting the ignitor electrodes until you get a strong spark every time. (With the gas tank valve off, of course.)

[Timex]

How do you adjust the igniter electrodes?

[RamblerGuy]

I removed the burner, and was able to reach in with some pliers and squeeze the electrodes closer. The pliers I had just barely fit. You may have to remove the electrodes to adjust them. The manual may have guidance on the desired gap. I just squeezed them and after a try or two I got a good spark every time.

[5picker]

Originally Posted by RamblerGuy

I removed the burner, and was able to reach in with some pliers and squeeze the electrodes closer. The pliers I had just barely fit. You may have to remove the electrodes to adjust them. The manual may have guidance on the desired gap. I just squeezed them and after a try or two I got a good spark every time.

Be careful squeezing the electrodes with pliers. They are housed in ceramic which can break/crack easily.

[RamblerGuy]

Good suggestion. Reminds me that I was a bit nervous doing it.

[gasman6674]

Its called delayed ignition. Make sure you have a good strong pilot when it lights, if not try to clean it. If it sparks direct to the burner make sure you have a strong spark and adjust the electrode (which you have ) improve it. Clean the area with a small brush and canned air if you can. There are a bunch of videos and articles on you tube to show you pictures and how to

Good Luck

[Timex]

Are the electrodes similar to the end of a spark plug that needs a little sanding to clean the tips up?
Or just wipe them to clean them?
If they are ceramic, I don't want to hear that fateful crack.

[wmtire]

Originally Posted by Timex

Are the electrodes similar to the end of a spark plug that needs a little sanding to clean the tips up?
Or just wipe them to clean them?
If they are ceramic, I don't want to hear that fateful crack.

Actually it's an electrode assembly, as in one.




If you will look at your posted pics in the OP, the rust color wire (I think it's the third or fourth pic, is connected to the electrode assembly spade terminal like in the above pic. This is what makes the electric spark. If you look at the pic above, there needs to be certain proper gap between the two ends, for a good spark.... and you can also adjust the entire assembly a hair using the set screw to make sure it aligns at the right place at the end of the burner tube.

[Timex]

I'm kind of leery about turning those rusty screws and what might happen. It will take me a week or two to get the materials and have some time to work on them. Thanks for all the advice. I'll come back with some more pictures and hopefully some good results. Thanks.🔥

[Timex]

Ok ya'll, I took the burner flue off and cleaned it real good inside. There was nothing that I could see(shining a light thru 1 end) but I wiped it good with a nylon brush.
Reached in with a stiff brush as far as I could reach in the burn chamber and cleaned as best I could.
Vacuumed all the loose rust debris, wiped the igniter electrodes, then used my leaf blower to blow everything else out.
Turned the switch on to see the spark for the igniter. Looked good to me. Went thru 2 cycles and it sparked each time.
Connected the flue back up.
Turned the gas on and it lit up like a champ.
Turned it off and then back on to relight.
Worked as it should.
No blow out. And no boom.
Attached is more pics.
The igniter tips are a lighter color in 1 pic because of the light I was using was shining on them.
I did find a screw loose on the bracket that holds the manifold in place. I don't believe that has anything to do with my problem though.
I don't know if anything I did made a difference. It might not do it again or it might do it again on the next trip out.
Granted, I didn't run it for complete cycles but only to see if it was lighting correctly.
If I have more time, I'll hook up a hose and run the water thru the faucets and really give it a workout.

My new pics aren't showing up in my post preview. I may have to repost.

[Timex]

For some reason my pics(5) are not coming thru.

I'll try 1 at a time.