Furnace locks out with E5 after ignition; burners light but shut off quickly, or blower runs without heat.

Critical safety warning: Flame rollout and limit trips can indicate a dangerous condition including potential carbon monoxide. If you see signs of scorching around the burner compartment or smell exhaust, shut the system down and call a professional immediately.

Basic homeowner checks (only if no visible damage):

• Turn off power and gas.
• Inspect the burner compartment for heavy soot, melted wiring, or scorched paint. If present, do not restart the furnace.
• Check that the front panel is properly installed and that return and supply registers are not blocked.
• Inspect the filter; replace if dirty to ensure proper airflow.
• Locate the rollout switches near the burners on your Westinghouse furnace. Some are manual reset (small red button). If one has tripped, press the button to reset once.
• Restore power and gas and observe operation. If the switch trips again, shut down and call a technician.

Professional service needed: A technician should inspect the heat exchanger, flue, and burner alignment. Do not repeatedly reset rollout switches without finding the cause.