I have the amana ams80905cna, the light does not flash a code (or maybe i'm looking at it wrong) but the heat will come on and ignite for approx 3 seconds before shutting off, then re-starting and shutting off again almost right away. if i shut off the power for a day, it will work fine for 2 or 3 days, then start this again. the thermostat is new and works fine, i have cleaned the ignitor, which was new in '09. any ideas?