Armstrong Air Furnace 8 flashes: What It Means & How to Fix It
Compiled & reviewed by the HVAC Flash Codes editorial team · Updated 2026-06-25 · confidence: high
⛔ Stop — call a licensed pro
What does Armstrong Air furnace 8 flashes mean?
Rollout switch open — the flame-rollout safety has opened, indicating flames or excessive heat outside the normal burner path. This switch typically requires manual reset. Most often caused by A blocked or failed vent / combustion-air problem causing flame rollout.
What your furnace LED does. The diagnostic light blinks 8 flashes, pause, repeat — that pattern is Armstrong Air furnace 8 flashes.
What Armstrong Air furnace 8 flashes means
Rollout switch open — the flame-rollout safety has opened, indicating flames or excessive heat outside the normal burner path. This switch typically requires manual reset.
Common causes
A blocked or failed vent / combustion-air problem causing flame rollout
A cracked or blocked heat exchanger
Plugged burners or improper combustion
Homeowner-safe steps to try
Turn the furnace off and leave it off — do not reset the rollout switch yourself
Do not relight burners or run the furnace until inspected
Keep the area clear and arrange professional service promptly
When to call a licensed HVAC technician
If the basic checks below don't clear the code, the fault recurs, or anything involves the gas valve, burners, flame sensor or wiring, stop and book a licensed HVAC technician. Repairs to the combustion or gas system are not DIY.
⚠️ Safety first. Gas furnaces burn fuel and produce combustion gases. If you ever smell gas (a rotten-egg or sulfur odor), hear hissing, or your carbon-monoxide alarm sounds, do not touch light switches, thermostats, or the furnace — leave the home immediately and call your gas utility's emergency line or 911 from outside. Homeowners should limit themselves to simple, safe steps: setting the thermostat, checking and replacing the air filter, confirming the furnace switch and breaker are on, keeping supply registers and return grilles open, and clearing snow, ice, or debris from outdoor vent and intake terminations. Never bypass, jumper, or reset safety switches (limit, flame-rollout, or pressure switches), never open the gas valve or burner compartment, and never attempt combustion, electrical, or control-board repairs yourself. Error codes point toward a problem but are not a substitute for proper diagnosis — when in doubt, turn the system off and call a licensed HVAC technician. Keep working carbon-monoxide detectors on every level of your home.
When to call a pro: Call a licensed HVAC technician immediately — flame rollout indicates a combustion/venting/heat-exchanger fault and a carbon-monoxide risk. Do not bypass the rollout switch. If a CO alarm sounds, you feel ill, or you smell gas, leave and call 911 or your gas utility from outside.
Armstrong Air furnace 8 flashes FAQ
What does Armstrong Air furnace 8 flashes mean?
Rollout switch open — the flame-rollout safety has opened, indicating flames or excessive heat outside the normal burner path. This switch typically requires manual reset.
What causes Armstrong Air furnace 8 flashes?
Common causes: A blocked or failed vent / combustion-air problem causing flame rollout; A cracked or blocked heat exchanger; Plugged burners or improper combustion.
Can I fix Armstrong Air furnace 8 flashes myself?
You can safely try: Turn the furnace off and leave it off — do not reset the rollout switch yourself; Do not relight burners or run the furnace until inspected; Keep the area clear and arrange professional service promptly. Call a licensed HVAC technician immediately — flame rollout indicates a combustion/venting/heat-exchanger fault and a carbon-monoxide risk. Do not bypass the rollout switch. If a CO alarm sounds, you feel ill, or you smell gas, leave and call 911 or your gas utility from outside.
Sources: firstsupply.com. General information for homeowners, not professional advice — confirm against your furnace's manual and a licensed technician.