Heil furnace LED flashes 5 times; furnace may start but shuts down, or will not start, often associated with rollout or flame safety issues.

Critical safety warning: A flame rollout condition can indicate a dangerous heat exchanger or venting problem that can lead to fire or carbon monoxide. Do not repeatedly reset rollout switches without finding the cause.

Steps to check (visual only for homeowners):

• Turn off power and gas: Use the service switch and gas shutoff.
• Locate rollout switches: Small manual-reset switches near the burners with a red or white reset button. If tripped, the button will be popped out.
• Inspect burner area: Look for signs of soot, scorch marks, or melted wiring around the burner compartment. These are signs of serious combustion issues.
• Reset once only: If there are no visible signs of damage, you may press the reset button on the rollout switch once. Restore power and gas, then call for heat and observe. If it trips again, shut the system down and call a professional immediately.

When to call a pro: Always have a licensed HVAC technician inspect a Heil furnace that has tripped a rollout switch. They must check the heat exchanger, venting, and combustion to ensure safe operation and replace the rollout switch if defective.