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water heater flame fades out

23hotrodr
Explorer
Explorer
We have an Atwood 10 gallon water heater with spark ignition. On this last trip, the water heater would light and then the flame would fluctuate a lot. Many times it would start out strong and then go down to nothing and the unit would attempt to relight. Sometimes this would be successful, and sometimes not.

All other gas appliances work properly-- stove, furnace, refrigerator. the gas valve assembly appears to have 2 gas valves and a small regulator . I suspect this gas valve assembly is faulty. I have confirmed proper gas flow to the valve.

Anyone else seen this problem? Any other ideas before I replace the gas valve assembly?

Thanks-- Mick
2007 Itasca Suncruiser 35L
2000 Jeep Wrangler
17 REPLIES 17

23hotrodr
Explorer
Explorer
SCVJeff wrote:
23hotrodr wrote:
SCVJeff wrote:
OP- What's the year and make of the RV ? There were several years of both ITASCA and Winnebago units that exhibited this exact problem from air starvation. Some did it, others not, and there was no reason why.


It's a 2007 Itasca Suncruiser. What is the solution?
I'm assuming that your WH is BEHIND a coach door, correct ? I looked around for 2007 Suncruisers and they appear to have the same behind the coach door access that mine does.

The good news is that you also have a slat punched into the outside door. The bad news is apparently Winnebago and Atwood never got together on this because its the vent to nowhere except a closed Atwood door.

On mine I punched 3ea. 3/4" holes into the Atwood door, making sure they align properly with the coach door when closed.

Second (and believe it or not, this is the Atwood fix) I removed the weather stripping from the bottom of the Atwood door, then bent out the center of the door toward you.

This will fix the problem nicely. As I said above, some have this problem, others not. When mine was new I had it in the shop and they literally swapped out everything but the tank itself, although I believe they were the ones that bent the door out, I finished it with a deeper bend. I finally left and figured out the missing vent holes myself. Sans bending the door I have heard of others punching holes into the bottom of the tank just behind the door, but my bent door works fine.

Good luck

BTW- I'm assuming that leaving the doors open lets the WH operate properly?

PS- While you're in there, burnish all of the various metal pieces from the chassis to the burner assy.. Any corrosion between those two will cause anything from intermittent flame to none at all. I'm the proud owner of a replacement control board when mine died hours before heading to Quartzsite.

Heres a shot of the door with the bend and the vent holes. I've since installed copper screen on the holes.


I always thought it was strange that there wasn't any holes or louvers behind the slot in the outer compartment door. The outer compartment door also makes the thing a royal pain to work on! They didn't provide anything to hold up the door and it will only open out to 90 degrees when the slide is out. I use an adjustable lenth painter's pole to prop it open

I'll have to make some of your modifications to get it more air. I really had problems when we were out in the Black Hills last week. The air is a lot thinner there than it is here at 700 feet.

Thanks for all the help. -- Mick
2007 Itasca Suncruiser 35L
2000 Jeep Wrangler

SCVJeff
Explorer
Explorer
Gene&Ginny wrote:
23hotrodr wrote:
... The gas valve makes a "thunk" (noise of closing) after the flame peters out. ....
That tells you that the flame sensor and probably the control board are working as they should. Loss of flame causes the control board to release (shut off) the LP valve. That narrows it to a flow or mixture problem.
yep.. It's starving for air, flameout, valve closed
Jeff - WA6EQU
'06 Itasca Meridian 34H, CAT C7/350

Gene_Ginny
Explorer
Explorer
23hotrodr wrote:
... The gas valve makes a "thunk" (noise of closing) after the flame peters out. ....
That tells you that the flame sensor and probably the control board are working as they should. Loss of flame causes the control board to release (shut off) the LP valve. That narrows it to a flow or mixture problem.
Gene and DW Ginny
[purple] 2008 Toyota 4Runner 4.7L V8 w/factory towing option
2002 Sunline Solaris Lite T2363[/purple]

Reese Dual Cam Straight Line HP Sway Control


Proud member of the Sunline Club

SCVJeff
Explorer
Explorer
23hotrodr wrote:
SCVJeff wrote:
OP- What's the year and make of the RV ? There were several years of both ITASCA and Winnebago units that exhibited this exact problem from air starvation. Some did it, others not, and there was no reason why.


It's a 2007 Itasca Suncruiser. What is the solution?
I'm assuming that your WH is BEHIND a coach door, correct ? I looked around for 2007 Suncruisers and they appear to have the same behind the coach door access that mine does.

The good news is that you also have a slat punched into the outside door. The bad news is apparently Winnebago and Atwood never got together on this because its the vent to nowhere except a closed Atwood door.

On mine I punched 3ea. 3/4" holes into the Atwood door, making sure they align properly with the coach door when closed.

Second (and believe it or not, this is the Atwood fix) I removed the weather stripping from the bottom of the Atwood door, then bent out the center of the door toward you.

This will fix the problem nicely. As I said above, some have this problem, others not. When mine was new I had it in the shop and they literally swapped out everything but the tank itself, although I believe they were the ones that bent the door out, I finished it with a deeper bend. I finally left and figured out the missing vent holes myself. Sans bending the door I have heard of others punching holes into the bottom of the tank just behind the door, but my bent door works fine.

Good luck

BTW- I'm assuming that leaving the doors open lets the WH operate properly?

PS- While you're in there, burnish all of the various metal pieces from the chassis to the burner assy.. Any corrosion between those two will cause anything from intermittent flame to none at all. I'm the proud owner of a replacement control board when mine died hours before heading to Quartzsite.

Heres a shot of the door with the bend and the vent holes. I've since installed copper screen on the holes.
Jeff - WA6EQU
'06 Itasca Meridian 34H, CAT C7/350

23hotrodr
Explorer
Explorer
gatorcq wrote:
control board. Sensor ID that is is lite to the board, if the board is not working then it just turns off the valve. I installed a new unit, it lite 1 time and the board went out.
Warranty


The gas valve makes a "thunk" (noise of closing) after the flame peters out. After a few seconds, it attempts to relight and is often a weak flame or fails.
2007 Itasca Suncruiser 35L
2000 Jeep Wrangler

gatorcq
Explorer
Explorer
control board. Sensor ID that is is lite to the board, if the board is not working then it just turns off the valve. I installed a new unit, it lite 1 time and the board went out.
Warranty
Dale & Susan
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23hotrodr
Explorer
Explorer
SCVJeff wrote:
OP- What's the year and make of the RV ? There were several years of both ITASCA and Winnebago units that exhibited this exact problem from air starvation. Some did it, others not, and there was no reason why.


It's a 2007 Itasca Suncruiser. What is the solution?
2007 Itasca Suncruiser 35L
2000 Jeep Wrangler

Old-Biscuit
Explorer III
Explorer III
Check the DC voltage on gas valve solenoids when flame lights off...then continue checking DC Voltage when flame starts fluttering/fading off.

Circuit board holds voltage on solenoids to keep gas valve wide open.
Voltage should be steady then completely off...........not fluctuate

'Valve Track' circuit on circuit board could have intermittent issue.
Is it time for your medication or mine?


2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31

SCVJeff
Explorer
Explorer
OP- What's the year and make of the RV ? There were several years of both ITASCA and Winnebago units that exhibited this exact problem from air starvation. Some did it, others not, and there was no reason why.
Jeff - WA6EQU
'06 Itasca Meridian 34H, CAT C7/350

Tin_Pusher
Explorer II
Explorer II
If you haven't done so aready, check the orifice. Maybe a little piece of "stuff" floating around.
Tin Pusher's Guide To Successful RV'ing: "Don't get mad, don't get in a hurry"

2002 1500HD
2002 Wilderness 265H
1997 Seadoo GTI
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Chris_Bryant
Explorer II
Explorer II
You say the burner has been blown out- if you have not, you need to run a brush through it. Blowing out doesn't always get spider webs, and it only takes a bit of web in the tube to disrupt the flow.
-- Chris Bryant

Ranger_Smith
Explorer
Explorer
Sounds like a fuel pressure problem
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23hotrodr
Explorer
Explorer
The burner is clean and has been blown out. I have disconnected the gas line from the valve and get good flow. The thing that gets me is that it burns great and then fluctuates and diminishes down to where the flame goes out. The air control that can be adjusted seems to be correct since when the flame is burning strongly, it looks great. All this is clean and free of obstructions. I have also blown out through the flue to make sure it is free of obstructions and it seems to be venting properly when the burner is burning normally.

Stumped-- Mick
2007 Itasca Suncruiser 35L
2000 Jeep Wrangler

Chris_Bryant
Explorer II
Explorer II
Road Runners wrote:
I am not sure how the burner on your hot water heater works, but if it is like the burner in my refrigerator it could be the burner is clogged with rust. If so, try cleaning the burner and see if that solves your problem.


Good point- should really be the first step.
-- Chris Bryant