vbmenu_register("postmenu_25846", true); , I'm experiencing a similar problem.
I have learned that on my Rheem, the microprocessor checks for safety conditions at different times. Not only it checks for the flame to be present, after igniting it, but it checks for the flame sensor to show continuity before flames are present.
If the excess temp sensor is open or the flame sensor is open in the early part of the power up sequence, the furnace will abort power up sequence and the blowers will run continously.
If excessive temp will trip the "round" sensor and open the circuit later on, it would also stop heating as well.
In other words, it appears that the microproccesor checks that the sensors are closed when they are supossed to be closed (before powering up) and open when there is a malfunction.
Are there any other switches I should check.
I think that the easiest way to check the "excessive burner area temp" sensor is to measure voltage across its terminals. (In my furnace, there is another sensor which measures air temp @ the plenum area) If you measure any voltage, that means that the sensor is open and needs to be resetted or replaced. I'm referring to the round sensor near the flame area which could be resetted by pressing the bottom. (Not the flame sensor)
Just be aware that 110 volts are present in the area, be careful.
On my furnace, the flame sensor was open all the time. I shorted the terminal to ground and the furnace will then continue the power up process, turning igniter on and gas valve on. However, because the flame sensor is not just a simple on/off switch, and the microprocessor expects certain resistance to ground and I merely put zero resistance to ground, the furnace stops after a few seconds of normal operation.
My present problem is explained under another thread, posted at 8:46 PM PacificTime Monday "Furnace power up problems" It was read but I didn't get any responses yet.
Hope my explanation fits your furnace and your problem.
Good luck, Abel