Furnace power up problems
Thanks Rusty for your response.
I have been reading other threads and have learned quite a bit from you and the other experts. I appreciate your support.
Back to your questions....
Yes, the unit has the three light board. The two green ones are on all the time and the amber which blinks and it is likely to be providing a failure code. However .... I don't have the code to decipher it.
Nevertheless, the code may accurately report "defective flame sensor" because it is now open. However, as mentioned above, the installed replacement is now open too, which led me to ask if anybody had a "board gone bad" which fried the flame sensor.
Is not much left to suspect. Although I'm concerned about ordering the board and a new flame sensor (about $200), and finding out that something else (the transformer for example) is blowing up the board and the sensor.
By the way, I am assuming that the flame sensor is defective because it shows infinite resistance which stops the power on sequence immediately after the pipe vent motor starts. When I shorted the flame sensors, the original and the replacement, then it powers up to igniting and opening the gas valve, for a few seconds, and then shuts down.
Have you ever installed a new flame sensor and the board fried it?
Have you ever measured flame sensor resistance at room temp and/or high temp? Do you remember the readings?
Thanks again for your help