[yzhu]

The ignitor turns red, but it fails to start if I leave the front cover fully on. it will start if I remove the cover or leave enough space to let pressure out. what's wrong with it?

 

[carmon]

sounds like pressure switch not making

 

[beenthere]

Is it a condensing furnace? Could be a problem with the secondary.

 

[yuri]

9200 is a 92% high. check venting for obstructions.

 

[HVACTECH96]

check intake pipe where it goes into the black combustion air connector.There is usually a white disk that catches leaves.