Furnace blower won't shut off

The indoor blower keeps running after the heat call ends.

Heating

normal

Possible cause

Limit and Rollout Switches
Component
Temperature safeties that shut down heating equipment, and what each one is actually reporting.
Thermostats and Control Wiring
Component
What each control wire does, how thermostat types differ, and how to troubleshoot a control circuit.

Local Code Notice

HVAC installation, venting, combustion air, ventilation air, gas piping, clearances, termination locations, electrical requirements, permits, and equipment requirements vary by jurisdiction and equipment. Always verify the applicable local codes, adopted code edition, regulations, permits, and manufacturer installation instructions before installation or service.