I have a goodman 80% furnace in my barn dated 1999 it runs for about 5-10 minutes then flame kicks off for about 2 minutes and re-lites, it does not go into lockout mode (keeps cycling this way) when t-stat reaches called for temp furnace will shut down til called for again.... i have replaced the limit switch already. Flame sensor would not be the problem because it heats for 5-10 minutes at a time, however i did clean it with scotchbrite pad to rule out that possibility.... i am using the bottom of furnace for cold air and no filter.. furnace is hanging 42"above floor... confused......

I have a Goodman 80% furnace in my barn dated 1999 it runs for about 5-10 minutes then flame kicks off for about 2 minutes and re-lights. It does not go into lockout mode (keeps cycling this way). When t-stat reaches called for temp furnace will shut down til called for again.

I have replaced the limit switch already. Flame sensor would not be the problem because it heats for 5-10 minutes at a time, however I did clean it with scotchbrite pad to rule out that possibility. I am using the bottom of furnace for cold air and no filter. Furnace is hanging 42"above floor.