Furnace displays E7 and shuts down shortly after ignition, sometimes with rumbling or popping

Critical safety warning: A flame rollout condition can indicate a serious safety hazard including risk of fire or carbon monoxide. If you see signs of scorching around the burner compartment or smell strong combustion odors, turn OFF the furnace and gas supply immediately and contact a licensed HVAC technician.

• Do not repeatedly reset: If your Kelvinator furnace has manual-reset rollout switches, do not repeatedly press the reset button without finding the cause.
• Visual inspection: With power and gas OFF, remove the burner door and look for signs of soot, melted wiring, or scorch marks around the burners and front of the heat exchanger.
• Check venting: Inspect the flue pipe for disconnections, severe rust, or blockages at the roof or sidewall termination. Do not operate the furnace with a disconnected flue.
• Reset rollout switch (only once): If there is no visible damage, you may gently press the red reset button on the rollout switch. If it immediately trips again when the furnace runs, shut the system down and call a professional.
• Professional evaluation: A technician should inspect the heat exchanger, combustion air supply, and venting system thoroughly before the furnace is returned to service.