Atwood 6 gallon LP/Electric DSI problem

OK everyone, I fixed it! I did talk to Atwood a couple of times this morning and he suggested I take the module to a local RV dealer and have it tested. That worked just fine. The dealer suggested a new sparker/sensor perhaps. That was $50 so I said no.

I called Atwood, and he said jumper out the T-Stat by removing the wires and jumpering them. That did not work. But wait a minute. In on of the leads that go to the thermostat connections there is a diode like device.

Called Atwood again, asked what this was. Apparently is is a fusible link that will melt and shut off the gas relay if there is a fire in the vicinity of the link. I pulled the plug in connections off the fusible link and jumpered the wires again. PRESTO!

The fusible link is just fine, it read 0 ohms in both directions, (which a diode would not do), but the spade connections were all crusty and ugly with corrosion. Squeezed off the old, cleaned up the ends, replaced the spades with new and away we go again. Yippee!

I had similar problem which was resolved by removing the small electronic board and cleaning the plug contacts using an eraser.Works every time.

I had exactly the same symptoms on my American Appliances (bought out by Suburban a LONG time ago) 6 gallon DSI heater. Outside it is not pretty, but inside the tank looks great. I replaced the flame sensor and no dice. The solution was a Dinosaur Electronics replacement board for $80. Now it works great.

Jose

You'll damage a thermocouple with steel wool. It's best to use a brass brush.

Thanks rjxj, I have indeed done the service manual detail. Just finished unscrewing the sensor and cleaning up the grounding screw and steel wool polished the tips. Will try again tomorrow as it's too dark to see now.

On the plus side, the electric heater is working just fine.

As the flame touches that thin wire probe it sends a millivolt signal to the card. It's different than the old thermo couple systems. Seems like voodoo but that's what it does. Be sure the probe/sensor is in the flame. Be careful to not crack the porcelain insulator if tweaking it. If it's newer you shouldn't have connection problems but it wont hurt to unplug and plug them back in to re establish a good connection.
Google that model number for a service manual and it will take you through all the steps.

Well this one is like new, essentially. If anyone has any insight as to how the igniter/sensor actually changes it's function from a sparking device to a thermocouple, and might have any input on how long the burner should run to give the sensor time to sense before shutting down, that would seem to be the problem.

Everything checks out with propane, furnace, stove, oven all working well. The burner fires almost immediately once the switch is on. The first pass is about 6 seconds, then subsequent tries are very much shorter, maybe only 1.5 seconds before it trips and puts on the red light.

Welcome to the club. Mine did the same thing. I went through all the checks for bad connections and bad igniter/sensor and replaced it. It was actually a bad circuit board. With mine being 14 years old I just replaced the water heater.