When the temperatures drop in Canada, a reliable furnace is essential for keeping your home warm and comfortable. Armstrong furnaces are known for their efficiency and durability, but like any heating system, they can develop issues over time. The good news? These furnaces are equipped with diagnostic lights that flash specific patterns—known as Armstrong Furnace Error Codes: Common Issues and How to Fix Them.
Understanding these codes can save you frustration, repair costs, and downtime without heat. In this detailed guide, we’ll explain what the error codes mean, common problems that trigger them, and practical steps you can take to fix them—or when to call in experts like GM HEATING AND COOLING INC for professional furnace repair in Canada.
What Are Armstrong Furnace Error Codes:
Armstrong furnaces use a built-in LED diagnostic system located on the control board. When something goes wrong, the light blinks in a sequence that corresponds to a specific error code. By counting the flashes and referring to the error chart, you can identify whether it’s a minor issue like a dirty air filter—or a major safety problem requiring immediate attention.
This makes troubleshooting easier and ensures homeowners aren’t left guessing about furnace malfunctions. However, while some issues can be resolved with simple fixes, others should always be handled by a licensed HVAC professional.
How to Read Armstrong Furnace Error Codes:
Before diving into specific error codes, here’s how you can read them:
- Locate the LED Indicator Light – Usually visible through a small window on the furnace’s front panel.
- Count the Flashes – The light will blink a set number of times, pause, and repeat the sequence.
- Check the Code Chart – Match the blinking pattern to the error code list.
- Don’t Reset Immediately – Turning off the furnace before noting the code will erase the diagnostic signal.
Knowing how to read Armstrong Furnace Error Codes: Common Issues and How to Fix Them is the first step toward fast, effective troubleshooting.
Armstrong Furnace Error Codes:
Below is a detailed breakdown of the most common Armstrong furnace error codes, what they mean, and how to address them.
1 Blink – Unexpected Flame Detected
Meaning: The system senses a flame when there shouldn’t be one.
Cause: Faulty gas valve, malfunctioning flame sensor, or wiring issue.
Fix: Shut down the furnace immediately and call a professional, as this could be a serious safety hazard.
2 Blinks – Pressure Switch Stuck Closed
Meaning: The furnace detects airflow when it should be off.
Cause: Faulty pressure switch or wiring problem.
Fix: This requires professional inspection to ensure safety and proper operation.
3 Blinks – Pressure Switch Stuck Open
Meaning: The furnace isn’t detecting airflow when it should.
Cause: Blocked vents, clogged air filter, or inducer motor failure.
Fix: Replace or clean the air filter, check for obstructions, and ensure vents are clear.
4 Blinks – High-Limit Switch Open (Overheating)
Meaning: The furnace is overheating.
Cause: Restricted airflow, dirty filter, blocked ducts, or blower issues.
Fix: Replace the filter, clear obstructions, and ensure proper airflow. If the issue persists, call a technician.
5 Blinks – Rollout Switch Triggered (Safety Hazard)
Meaning: Flames are escaping the heat exchanger.
Cause: Cracked heat exchanger, blocked flue, or combustion problem.
Fix: Turn off the furnace immediately and contact GM HEATING AND COOLING INC—this is a dangerous issue.
6 Blinks – Pressure Switch Lockout
Meaning: The switch has tripped multiple times.
Cause: Venting issues, frozen intake/exhaust, or defective switch.
Fix: Requires professional diagnosis and repair.
7 Blinks – Ignition Failure
Meaning: The furnace attempted to light but failed.
Cause: Dirty flame sensor, cracked ignitor, or gas supply issue.
Fix: Clean the flame sensor, check the ignitor, and ensure gas is flowing.
8 Blinks – Flame Loss
Meaning: The flame started but then went out.
Cause: Gas supply interruption, dirty sensor, or burner problem.
Fix: Clean the sensor and check the gas pressure. Persistent problems require technician service.
9 Blinks – Reversed Polarity
Meaning: Electrical wiring issue.
Cause: Power connections installed incorrectly.
Fix: A licensed electrician must correct this issue.
Preventing Armstrong Furnace Error Codes:
While error codes are helpful diagnostic tools, the best way to deal with furnace problems is to prevent them before they start. Here are maintenance tips from GM HEATING AND COOLING INC to keep your Armstrong furnace running smoothly in Canada:
- Change Air Filters Regularly: Replace every 1–3 months.
- Keep Flame Sensor Clean: Prevents ignition failures.
- Inspect and Clean Vents: Blocked vents cause pressure switch problems.
- Schedule Annual Tune-Ups: Professional maintenance catches small issues before they escalate.
By following these steps, you can minimize the chances of encountering Armstrong Furnace Error Codes: Common Issues and How to Fix Them.
When to Call GM HEATING AND COOLING INC
While some furnace issues can be solved with basic troubleshooting, many require professional help. Call GM HEATING AND COOLING INC if you experience:
- Repeated or recurring error codes
- Strange noises, gas smells, or frequent shutdowns
- Overheating or flame rollout problems
- Electrical issues like reversed polarity
Our team provides expert Armstrong furnace repair, replacement, and maintenance across Canada. With 24/7 emergency service, we ensure your home stays warm and safe throughout the winter.
Conclusion
Understanding Armstrong Furnace Error Codes: Common Issues and How to Fix Them helps homeowners diagnose furnace issues quickly and avoid costly downtime. While some fixes—like replacing filters or cleaning sensors—are simple, others require expert HVAC services.
For reliable furnace repair and maintenance in Canada, trust GM HEATING AND COOLING INC. Our skilled technicians are equipped to handle Armstrong furnace troubleshooting, repairs, and replacements to keep your home warm and energy-efficient all winter long.
FAQs
Q1: What’s the first step if my Armstrong furnace shows an error code?
Record the flashing sequence before resetting. Then, compare it to the error chart.
Q2: Can I reset my Armstrong furnace to clear an error code?
Yes, turn off the breaker for 5 minutes. If the code returns, the problem needs further inspection.
Q3: What’s the most common cause of furnace ignition failure?
A dirty flame sensor or faulty ignitor. Cleaning or replacement usually fixes it.
Q4: How often should I schedule furnace maintenance in Canada?
At least once a year, preferably before winter.
Q5: Should I repair or replace my Armstrong furnace?
If your unit is over 15 years old and requires frequent repairs, replacement may be more cost-effective.