Bryant short ignite cycle - sometimes

[hobbyjeep]

I have a 15 year old Bryant 80% gas furnace and have never had a problem. Normally, after the igniter glows, I hear the burner ignite, then 90 seconds (estimate) later the blower motor starts, and we get heat.
The past few weeks, sometimes I hear the burner ignite, then very shortly after (10 seconds est) the blower starts, but then the furnance shuts down and goes through the start up process again. Usually it cycles properly the second time and furnace starts.

Last night, furnace must have done this a few times, and it shut down - woke up house was 60 degrees, flashing code 13. Ive reset code

What it causing it to have a short ignite cycle and what any suggestions what I need to check/replace would be appreciated.
thanks

[HayZee518]

check the flame detector. it will be one of two items - a millivolt generator or a flame detector rod.

[paul52446m]

I have a 15 year old Bryant 80% gas furnace and have never had a problem. Normally, after the igniter glows, I hear the burner ignite, then 90 seconds (estimate) later the blower motor starts, and we get heat.
The past few weeks, sometimes I hear the burner ignite, then very shortly after (10 seconds est) the blower starts, but then the furnance shuts down and goes through the start up process again. Usually it cycles properly the second time and furnace starts.

Last night, furnace must have done this a few times, and it shut down - woke up house was 60 degrees, flashing code 13. Ive reset code

What it causing it to have a short ignite cycle and what any suggestions what I need to check/replace would be appreciated.
thanks

If you have a glow bar then you will have a flame rod. It looks like a nail coming
up by a burner, take some fine sand paper and clean the flame rod and that might make her work. Later paul

[hobbyjeep]

Will sandpaper the rod, I see it in the furnace. Thanks

Would that cause the blower to start sooner than normal? any idea how long the burner should burn (after ignition) before the blower starts? Sometimes they seem to be within a few seconds of each other... other time seem a lot longer

thanks
Cold in Michigan

[paul52446m]

Will sandpaper the rod, I see it in the furnace. Thanks

Would that cause the blower to start sooner than normal? any idea how long the burner should burn (after ignition) before the blower starts? Sometimes they seem to be within a few seconds of each other... other time seem a lot longer

thanks
Cold in Michigan

The blower should not come on for 30 to 60 sec. after burner. But if burner went out on safety the the board can run through other cycles. If the burners don't turn off on safety and the blower keeps coming on in 10sec. then that would be a problem in the board. Later Paul

[hobbyjeep]

Just a fyi - Last week I lightly sanded the flame rod - it had a light coating on it where it sits in the flame. After five days, furnace cycles like new... no false starts.

thanks for your help -