i have a goodman furnace that won't stay on .. the glow plug comes on and ignites the heat box,, it will run then shut off ...after it gets to desried heat ,,, then when u try to get it to run again it's like it shuts down after igniter being lit for about 10 secs,, i've replaced batteries in thermostat and had new filter installed aswell... it seems every time i go to loook at it i can get it to run as normall then my tenent calls and tells me it wont start after coooling of the house
two things are possible: there is a flame sensing rod in front of the far left hand burner. take a piece of steel wool and GENTLY clean it off by sanding the rod up and down. this sensing rod tends to condensate after a lot of cycles and collects lime calcium ect. If this doesnt work, I guarantee that the inducer motor is either loose or worn out. try tightening the screws that hold the motor on the heat exchanger. take a look and see if the red rubber gasket is intact.
good luck I have worked on hundreds of Janitrol/Goodman furnaces and these are the two main causes of flame failure.
