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View Full Version : Gas furnace Cycle Blows but no Flame


tiredmomps
Feb 28, 2008, 09:56 AM
We have a Comfortmaker Furnace that is about 3 years old. It will act like it is going to turn on with the blower moter kicking on but the flame never turns on.

Then the motor stops. Then about a minute later it repeats the cycle. It will do this for about 5-7 minutes several times a day.

I have had two repairmen come out and neither one can figure out the problem. They have checked every part and said it is working fine.

Help, any ideas what it could be?

Paula

hvac1000
Feb 28, 2008, 10:38 AM
Is the circuit board flashing a code? It should be if it is operating with a malfunction.

Be more specific. Does the burner light at all?

T-Top
Feb 28, 2008, 07:55 PM
I agree if your furnace is faulting out it will show a code from the blinking light. Look through the small round window on the blower door on the furnace and count the blinks. On the back side of the door it will give you the code of to what's wrong.

tiredmomps
Mar 3, 2008, 09:19 AM
In response to the comments, there is not a window in which to see the circuit board. The panel is solid. When I remove the panel to see what codes are being flashed the furnace shuts off.

More information, the blower motor goes on but the flame doesn't. This happens about 5-8 times in a row. Then either the blower and the flame starts or it stops completely.

It will stop for about 15-20 minutes and repeat the cycle.

Any ideas? This is driving me crazy!

Paula

hvac1000
Mar 3, 2008, 09:35 AM
((Then either the blower and the flame starts or it stops completely))

This is a shot in the dark on my part but the flame sensor might need to be cleaned on your unit if so equipped.

Something else you might try is to set the furnace up to run the hold in the safety switch until the furnace starts. At that point it should show a lit that is blinking. We need the number of blinks to really help you.