My 27 year old Carrier Super Saver furnace fan blower stays running even when the thermostat is off. After some troubleshooting, found out that fusible link connected to what looks like a limit switch P/N 4283A was blown. Replaced the fusible link, furnace ran fine for 15 minutes, then no heat, only cold air coming out of vents. Fan/blower keeps running. Whats causing the fusible link to blow. Filter underneath th
Its not the flue pipe. That is a seperate circuit with a different fault code. If you have air conditioning, check to see if the evaporator coil is dirty. Your furnace goes off on limit due to lack of airflow. Therolloutswitch is a manual reset so if you have reset it the furnace would not uave ever come back on.