Atwood water heater ignition acting strange...

[SJ-Chris]

I've got a 2006 Four Winds 31P with an Atwood water heater. I was out camping the other day for 2 nights. We had hot water on the first and second days. On the final morning of our trip the hot water heater would not start.

A few details...
- Yes, we had plenty of propane (the furnace was working fine).
- We were not at a high elevation (in case that matters)
- It was ~28 degrees F overnight

It is important to point out HOW it was failing, as I found that to be a bit strange. The normal operation in my rig when turning on the water heater is that I would toggle the switch on the control panel after making sure the propane tank valve is open. A RED light on the switch will turn on. A few seconds later I will hear the click-click-click of the ignitor, and then I would hear the whoosh of the gas igniting, and then the red light turns off.

What was strange on this cold morning is that when I toggled the water heater switch on the control panel the RED light never came on and there was no click-click-click. Therefore, the water heater did not ignite. I tried several times and nothing happened. So we didn't have hot water for the last day.

A day after I got home, I went to try it again and it functioned exactly how it is supposed to function. Toggle switch, red light comes on, click-click-click, ignites, then the red light turns off.

Has anyone seen a water heater behave like this? Any suggestions on how to fix it so that it doesn't happen again? I had a mechanic tell me that I should try changing the igniter and the toggle switch as those are possibly the problem.

Thoughts? Thanks in advance!!

-Chris

[wa8yxm]

Something that happneed to me

Gas would try try try to light then FAULT like 3 or 4 times with water heater cold, HOT no problem

Finally had to replace control board.

[dougrainer]

Usually, the Thermal Cut off just fails. But, as you found out, yours was bad, but by moving it, the sensor would make contac in the plastic sleeve. . Also, there is NO pilot flame. Just the Main flame. Doug

[SJ-Chris]

Update: The water heater ingition/operation continues to now function as it is supposed to...with one exception.

I flipped the ignition switch at the control panel and it ignited like it was supposed to. Then I opened up the external water heater compartment to take a look. The pilot was lit and operating. As I was touching the wires giving them each a little wiggle something happened. When I touched the thermal cutoff wire (gently) immediately the water heater shut off and the flame went out. One second later when I moved my hand off the thermal cutoff wire it immediately fired up again and operated as it should. Seems like this thermal cutoff wire is the culprit. I replaced it and it is now working once again.

Has anyone else seen this situation where the thermal cutoff wire seems a bit sensitive to touch/movement?

I'm hoping I fixed the problem, but I'll have to take it out for a couple days and use it to really feel comfortable that the problem is fixed.

Thanks!

[Dutch_12078]

If you have a common LP furnace like the Hydroflame 8500 or 8900 series, the igniter board is usually easy to remove and can be used as a substitute for the water heater igniter board for diagnostic purposes. It will work fine with just the same ~20 second delay that the furnace uses before it kicks in.

[theoldwizard1]

Chris Bryant wrote:
The 12 volt power goes from the switch through a flame fuse, thermostat, then to the ignition module. Any of these can interrupt the power- a meter or test light will tell you where the power stops.
Those flame fuses are flaky, but all of them, including just a bit of corrosion on the board connector, can give that failure- power not getting to the board, since you get no fault light.

Been there done that. I have tested all connection points with a 12V test light.

NOTE to other DIYers. Use a 12V INCANDESCENT test light. it proves that the connection can pass about 250mA of current. A meter will only show that there is voltage there, NOT that it can pass current.

[Ava]

The terminals at the water heater(as in the picture above) on mine needed cleaning to fix the exact problem. If the main 12v feed wire is not getting through, the red light by switch will not come on and no ignition.
On my Atwood unit, the red light also comes on when igniting, then goes out after lighting.

[theoldwizard1]

SJ-Chris wrote:

A day after I got home, I went to try it again and it functioned exactly how it is supposed to function. Toggle switch, red light comes on, click-click-click, ignites, then the red light turns off.

Has anyone seen a water heater behave like this?

My daughter has been fighting this since they bought their Jayco about 3 years ago. The dealer has "fiddled" with it 3 times with no real long term success.

My last attempt at fixing it was to remove the thermostats, clean the face of the thermostats and the area that they contact on the tank. It was about 70-95% successful repair. The odd thing is, it seems to light the first time about 95% of the time. Re-lighting is about 70%. They have learned that if the red light is on, turn the switch off for about 1 minutes and then back on. 95% success.

Worst case, carry on of those BBQ lighters. If the igniter does not start it immediately, light the burner with with the BBQ lighter.

[Old-Biscuit]

As Chris pointed out......doesn't take much corrosion or looseness to stop 12V DC


What I find different is the RED Fault light coming ON when you turn gas switch on then going out when flame lites/proves.

I know Suburban uses that circuit but Atwood Red Fault light only comes on when FAULT occurs.........???

[Chris_Bryant]

The 12 volt power goes from the switch through a flame fuse, thermostat, then to the ignition module. Any of these can interrupt the power- a meter or test light will tell you where the power stops.
Those flame fuses are flaky, but all of them, including just a bit of corrosion on the board connector, can give that failure- power not getting to the board, since you get no fault light.

[BFL13]

I had to replace the switch with the red light on it. Solved the problem.

BTW as a separate issue, the three clicks might indicate a problem developing. Would expect the thing to ignite right off and the red light go out same time.

[MDKMDK]

Does the Atwood manual indicate that a low 12VDC input power condition will prevent DSI ignition? I can't imagine why, but? Or, does it have a "low/no water" ignition prevention check? Perhaps the w/h thought it was empty and wouldn't allow the ignition cycle to start?

[eHoefler]

Since the light did not come on, I would look for a loose connection for the power supply.