Norcold 821L

Dirty burner tube.....rust flakes on slots etc

Bad circuit board

Old Biscuit is on target.

The igniter on the refrigerator is also a sensor. If flame isn't proven right after it sparks, it will wait a few seconds and try again a couple of times before a safety lockout. To get it to try again, you need to turn the refrigerator off and back on.

There's a unique thing about flames. They only allow DC current to pass. The control board sends an ac signal to the combination flame rod and igniter. It expects to sense a dc current when the flame is present. If it senses an ac current, it knows the flame rod is somehow shorted. Rust may have fallen on it allowing it to pass the ac signal and stopping the ignition process.

If you get up on the roof and remove the refrigerator vent cap, you can pull the spiral out of the flue and brush it off. Raise it up and down to knock all the flaky rust off the walls of the flue. Running a bottle brush (flue brush) up and down helps too. Vacuum out the burner area to remove all the fallen rust before trying it again.

If all that fails, it might be time to think about a control board.

Thanks for the feedback. I was leaning toward the mother board as well. I originally ruled out propane supply as the stovetop lit right up but when I checked the propane bottles, I noticed that the auto-switching propane regulator was on an empty bottle. I now suspect that when the bottle ran out, it would supply a large flow(stovetop) but not the fridge.I switched the supply to the full bottle and have not been able to get it to act up since. Perhaps the autoswitch was not operating properly after the long winter of not being used????