Thanks for the info. I've replaced the flame sensor, ignitor, and both thermostats just because they are easy to do and its not bad to have those around as replacement parts. What I have noticed from further testing after putting those parts in is that whereas the burner previously would always at least fire, now it won't!! I checked the voltages at the gas valve coils. Sometimes I get the correct voltage, and sometimes I get nothing at all. Also, one time I heard the valve open, gas coming out, and the ignitor wasn't on. With the goofy voltages I'm getting and the sequence seeming a bit off, I'm leaning towards a new circuit board....Any thoughts on this??