i have a goodman furnace and just the other nite i noticed the house wasnt heating, I checked the furnace and the indicator light suggested vent blockage checked the vent stack that leads to chimney and found 2 dead birds in stack removed them and started furnace, thought i had it fixed. all worked fine for about 5-8 mins. then kept cutting itself on and off again every 5 min. indicator light now says open limit switch/check limit switch.
dont have manual. what am i looking for? where would it be? if i find it, what do i do? Appreciate any advice i can get! Thanks

NorthernHeat

Check filters and blower, plugged evaporator coil or secondary heat exchanger. Furnace is overheating because not enough air is going through it to keep it cool.