Furnace runs briefly then shuts off; E5 code on control board

Critical safety warning: A rollout condition can indicate serious combustion or heat exchanger problems and risk of fire or carbon monoxide. Do not repeatedly reset rollout switches without finding the cause.

• 1. Power and gas off: Turn off the furnace power and close the gas shutoff valve.
• 2. Visual inspection: Remove burner access panel. Look for signs of scorching, melted wiring, or soot around the burners and rollout switches.
• 3. Check venting: Inspect the flue pipe for disconnections, crushing, or blockages. Do not operate the furnace with a blocked flue.
• 4. Rollout switch reset: Locate the rollout switches near the burner area. Some have a small red reset button. If tripped, press firmly until it clicks. Only reset once after verifying there is no visible blockage or damage.
• 5. Do not bypass: Never jumper or bypass a rollout switch. This is a critical safety device.
• 6. Professional inspection required: If the rollout switch trips again, or if you see flame coming out of the burner area, shut the system down and call a qualified HVAC technician immediately to inspect the heat exchanger, burners, and venting.