Flame Sensor

[cyberxaos]

I have a M1MB-077A BW Furnace.
Recently I have been getting Lockout due to failed ignition. This is a unit that I picked up for my garage. It worked fine for about a month. Then seemed to blow cold air occasionally. Until I finally got nothing but cold I decided to check it out.
It will start up fine. Exhaust, igniter glows, gas ignites, blower starts up and stays on, yellow flame light is steady for a few secs, then blinks and goes out. The flame of course dies. 4 more attempts. then lockout. Red light blinks 4 times. I am sure that I have a flame sensor that needs to be cleaned up. There is not one on this furnace. I do not even see one on the wiring diagram on the furnace panel. Does the igniter (that looks new and still functions) double as a flame sensor as well? If I purchase a new igniter will this fix the problem?

[Robert]

Hi,

I'm away from my regular office until late tonight or tomorrow afternoon. I will look it up at that time.


When there isn't a flame sensor seperate, then most often the ignitor doubles as the flame sensor.


I cannot say from here if that is the problem, that would require thorough testing of circuits and cycle sequences.




Thanks,
Robert