Lenox Furnace Problem

[jwichman]

I have a 11 year old Lenox G23Q2/3-75-2 furnace. The ignition module was replaced 5 or 6 years ago with a Honeywell, all has work great until just last week. During the heating cycle I noticed the combustion air blower shutting off and the flame going out, the main blower continues to run. Flame is out for approx 60secs then the combustion air blower starts and the flame re-ignites. It may do this 3 or 4 times during a heat cycle. Any thoughts or where/what I should check first?

Thanks,

[paul52446m]

I have a 11 year old Lenox G23Q2/3-75-2 furnace. The ignition module was replaced 5 or 6 years ago with a Honeywell, all has work great until just last week. During the heating cycle I noticed the combustion air blower shutting off and the flame going out, the main blower continues to run. Flame is out for approx 60secs then the combustion air blower starts and the flame re-ignites. It may do this 3 or 4 times during a heat cycle. Any thoughts or where/what I should check first?

Thanks,

Take flame rod out and clean it with some fine sand paper.
Make sure burners are clean and flame is steady around the flame rod.
A weak limit switch opening up could cause this problem. Is the combustion air blower running free and sounds like its up to a good CFM.
Does the combustion air blower have a end switch in it that might not be staying made? Any electric testing would have to be done in the 60 seconds
that the burner goes out. Do you have a electric tester? and it would help to see your wiring diagram. Later Paul

[jwichman]

Take flame rod out and clean it with some fine sand paper.
Make sure burners are clean and flame is steady around the flame rod.
A weak limit switch opening up could cause this problem. Is the combustion air blower running free and sounds like its up to a good CFM.
Does the combustion air blower have a end switch in it that might not be staying made? Any electric testing would have to be done in the 60 seconds
that the burner goes out. Do you have a electric tester? and it would help to see your wiring diagram. Later Paul

Thanks for the response. I troubleshot the problem by jumpering one switch at a time and running the furnace through a heating cycle. Turned out the rollout switch was shutting the blower and flame down which was due to an dirty filter. Changed out the filter and all is well.

[paul52446m]

Thanks for the response. I troubleshot the problem by jumpering one switch at a time and running the furnace through a heating cycle. Turned out the rollout switch was shutting the blower and flame down which was due to an dirty filter. Changed out the filter and all is well.

Those roll=out switches can get weak so if it gives you and more problem,
you might have to replace it. Later paul