Maddening water heater issues!

[HoneyBadger]

I really hope we can find some help with this. I'm pulling my hair out!

We have an Atwood G6A-8E water heater, which is a 6 gallon electronic ignition gas unit in an '89 Fleetwood.

The problem: the heater will not stay lit. The ignitor sparks, the gas lights off and burns for a few seconds and then shuts down. This will repeat 2 more times and then it locks out.

What we've done:
1) replaced the igniter/electrodes (first thought being that the "flame on" message was not being sent back to the control board.) The heater worked fine for the next 6 hours, then quit and went back to the original problem.

2) next, we checked the voltages, they were all at 12v or so. After poking around with the meter, heater again lit and ran for a few hours, then back to original problem.

3) replaced the ECO/thermostat (not for any particular reason, but we had a new spare). Again, the heater lit and ran for a few hours before reverting

4)Had the rig at an RV repair place for another issue, so we had them look at the W/H. They swapped out the control board for a new one, but the new board did not fix it so they put the old one back in. They replaced the thermal cutoff and the heater again lit and ran for a few hours.

5) Replaced the wiring harness, with exactly the same results as every other time. Lights, runs, quits after a few hours.

6) Also filled the propane tank, since it was pretty low, removed and cleaned the burner tubes, checked the flame spreader, made sure the air adjustment was correct. The flame seems to be the right color and shape.

Now, the only 2 components left unreplaced are the control board, which should be OK according to the RV repair guy, and the gas valve.

The ground connection is clean and tight. The light and switch inside on the panel work as they are supposed to.

Does anyone have any idea what is going on here????

We've downloaded the Atwood service manual, but the troubleshooting guide doesn't cover anything new.

Besides being a major pain not having hot water, this is getting expensive and infuriating.

I'd sure appreciate some feedback!

[calhyatt]

Originally Posted by Honey Badger

I really hope we can find some help with this. I'm pulling my hair out!

We have an Atwood G6A-8E water heater, which is a 6 gallon electronic ignition gas unit in an '89 Fleetwood.

The problem: the heater will not stay lit. The ignitor sparks, the gas lights off and burns for a few seconds and then shuts down. This will repeat 2 more times and then it locks out.

What we've done:
1) replaced the igniter/electrodes (first thought being that the "flame on" message was not being sent back to the control board.) The heater worked fine for the next 6 hours, then quit and went back to the original problem.

2) next, we checked the voltages, they were all at 12v or so. After poking around with the meter, heater again lit and ran for a few hours, then back to original problem.

3) replaced the ECO/thermostat (not for any particular reason, but we had a new spare). Again, the heater lit and ran for a few hours before reverting

4)Had the rig at an RV repair place for another issue, so we had them look at the W/H. They swapped out the control board for a new one, but the new board did not fix it so they put the old one back in. They replaced the thermal cutoff and the heater again lit and ran for a few hours.

5) Replaced the wiring harness, with exactly the same results as every other time. Lights, runs, quits after a few hours.

6) Also filled the propane tank, since it was pretty low, removed and cleaned the burner tubes, checked the flame spreader, made sure the air adjustment was correct. The flame seems to be the right color and shape.

Now, the only 2 components left unreplaced are the control board, which should be OK according to the RV repair guy, and the gas valve.

The ground connection is clean and tight. The light and switch inside on the panel work as they are supposed to.

Does anyone have any idea what is going on here????

We've downloaded the Atwood service manual, but the troubleshooting guide doesn't cover anything new.

Besides being a major pain not having hot water, this is getting expensive and infuriating.

I'd sure appreciate some feedback!

Is it shutting off due to an overheated condition ? Have you measured the water temperature when it quits. A meat thermometer would work. Just a thought..

[HoneyBadger]

Hmm- no I haven't measured the actual water temp, but it seems to shut off and relight appropriately (while its working, that is), and the temp of the hot water out of the tap seems normal

But I shall certainly do so the next time I can get the $#&*! to light.

[DCGarcia]

Well, it seems to me that the only other item you did not mention is the gas tubing itself. Might be some kind of strange blockage that is building up after awhile. Sorry, I have no idea how to check that out, except by using a propane bottle, some kind of gas line with all the necessary connections.


Dan

[Tony Lee]

I found the ground connection was very poorly designed and instead of having separate ground connections to the ignitor and the propane valve back to the board or a real ground, it relied on good connection from the ignitor section, back through the mixer tube and then to the solenoid valve body and then back to ground via the gas pipe and or mounting bracket. In your case the gradual heating up of these ground circuit components could be causing a bad ground that is causing the ignition sensor to show a no-flame condition so it shuts down until things cool down enough to re-establish the ground circuit.

[DCGarcia]

Tony Lee's suggestion is a good one. I would run a test wire from the ground point you checked and cleaned to the battery and a wire from the control board to the battery for starts. Sure is a lot easier then checking the copper tubing I suggested.

[BeltoneMagoo]

Having had the same problem one time, I will tell you what I did. cleaned all connections including the multi pin on the black module. Replaced the ignitor/sensor. Replaced the gas valve. Still had the problem. Read a whole lot about the system. Came to the conclusion that the new ignitor/sensor was bad and replaced it again. 3 years now and it still works fine. Seem that the ceramic that holds the ignitor/sensor rods can and do develop minute cracks that drain off the sensor signal to the black module. Since that signal is only on the order of microamps it is easy to see why a little loss can cause problems. Hope you find your problem and all goes well.
Good luck and safe travels!

[HoneyBadger]

Thank you for the suggestions! Had wondered if the new igniter could be bad- seemed unlikely but I'm sure willing to invest another $20 to check.

An inadequate ground is also a good point- I think I can run a new wire down to the frame and just tap it into the existing ground wire inside the cabinet in the bathroom.

I have been randomly and fruitlessly trying to light the water heater once or twice a day over the last few days- this afternoon, although nothing has changed it lit and is still burning.

Transient phenomena are the worst.

[bikermike]

I have a 1993 Fleetwood, our water heater stop working after a long weekend in the rain. I check everything could not find the problem just happed to bump the black box and it started working. One of the mounting screws is a ground and it had gotten wert and lost contact.

[baraff]

This sure sounds like the same problem I had with mine, it drove me crazy. It turned out the sensor probe had a small crack in the ceramic around the probe, where the probe enters the ceramic casing. It almost did not look like a crack but a seam. But it was cracked and that caused a voltage leak or short and it would not light. Or it would light and run a while but not relight.
I bought a replacement off eBay, cost around $26+shipping. I haven't had a problem since!

[cronin069]

i have an 89 fleetwood with an atwood water heater had the same problem. corrected it by moving the ground wire to a better spot works fine now hope this helps

[wa8yxm]

My Attwood furnace did that.. Turned out to be a bad control board.. If yours is a bad control board may I recommend Dinosaur boards (if that is they make one that fits your water heater).

I'm told Attwood has quality issues with their electroincs.. I believe it having looked at the two different boards side by side.. I was VERY impressed with the Dinosaur board's quality of workmanship and design... And I am certified as an electronics technician, Have done some of my own design and construction in other areas.

But I stress.. There are other possible causes.. And others are giving you a good list of suspects.. I'd eliminate those before I popped for a new control board.

I did, in fact, eliminate.. Well you get the idea.

[DCGarcia]

Hello Honey Badger,
Curious minds would like to know. Did you fix your water heater and what was the problem?
Thanks

[wickedrevs 56]

Agree, what was it? Both the ground feed to the control module. And the cracked flame sensor are common enough....