[gerry m]

I am having a problem with my luxaire 93% furnace. Every morning from about 4:00
a.m. till about 8:00 a.m. the furnace fan will start normally, the igniter will glow, the burner will fire up for about 5 sec. then it will shut down. after about 15 sec. it will start back up with its cycle and this time the burner will
run for about 15 sec. then shut down. the third or forth time it does this it
will stay fired and run normally through its cyle. Other times of the day it seems to run normally. I have replaced the igniter and checked that the air
intake and exhaust pvc pipes are clear. Any idea's-thanks

 

[HVAC Doc]

I am having a problem with my luxaire 93% furnace. Every morning from about 4:00
a.m. till about 8:00 a.m. the furnace fan will start normally, the igniter will glow, the burner will fire up for about 5 sec. then it will shut down. after about 15 sec. it will start back up with its cycle and this time the burner will
run for about 15 sec. then shut down. the third or forth time it does this it
will stay fired and run normally through its cyle. Other times of the day it seems to run normally. I have replaced the igniter and checked that the air
intake and exhaust pvc pipes are clear. Any idea's-thanks

Remove and clean the flame sensor rod. Use steel wool or plumbers cloth.

 

[NickTech]

make sure the flame engulfs the sensor, check the maniflod gas pressure with a manometer. it should 3.5" water column.

 

[gerry m]

Thanks-it worked

Thanks- I steel wooled the flame sensor and my problem went away.
This forum is great and I will try to help others with my area's of knowledge