Canadian winters demand reliable heating, and Carrier furnaces are built for just that. However, even high-performance systems can occasionally encounter issues. When that happens, your furnace will likely display a diagnostic error code.
So, what do Carrier furnace error codes mean? These alphanumeric or blinking light codes are your furnace’s way of telling you something’s not right. In this guide, we’ll walk you through how to read and understand these error codes, how to troubleshoot common problems, and when it’s time to contact the professionals at GM Heating and Cooling Inc.
What Are Carrier Furnace Error Codes?
Carrier furnace error codes are part of the system’s self-diagnostic mechanism. Instead of guessing what’s gone wrong, these codes help pinpoint the issue. Whether your furnace is not heating, not igniting, or cycling too frequently, the displayed code gives valuable insight.
Types of Error Codes:
- Alphanumeric Codes – Shown directly on the control panel or thermostat.
- LED Flashing Codes – Blink patterns on the circuit board indicate specific faults.
These error indicators are there to make troubleshooting easier and quicker, especially when handled by trained HVAC technicians.
Why Should You Care About Carrier Furnace Error Codes?
Ignoring furnace error codes can lead to:
- Reduced energy efficiency
- Increased energy bills
- Shortened equipment lifespan
- Complete system breakdown
For homeowners and businesses across Canada, addressing these codes promptly ensures a warm, safe, and energy-efficient environment. Common Carrier Furnace Error Codes (And What They Mean)
Below are some of the most common Carrier furnace error codes, along with their meanings and suggested solutions.
| Error Code | What It Means | Troubleshooting Tips |
|---|---|---|
| 13 | Limit Switch Lockout – Overheating | Check and replace air filters; unblock vents; let the furnace cool |
| 14 | Ignition Lockout – Igniter failed | Check the flame sensor and igniter; ensure the gas supply is on |
| 31 | Pressure Switch Open | Check for vent obstructions; verify tubing is connected |
| 33 | Limit Circuit Fault | Clean dirty filters; make sure airflow isn’t restricted |
| 34 | Ignition Proving Failure | Flame sensor may be dirty or faulty |
| 42 | Inducer Motor Fault | Check motor operation and clear any venting blockage |
| 21 | Gas Heating Lockout | Possible flame failure or gas valve issue |
| 24 | Secondary Voltage Fuse Open | Check for a blown fuse; inspect control board wiring |
| 44 | Blower Motor Fault | The flame sensor may be dirty or faulty |
Knowing these codes allows you to handle minor problems yourself or communicate clearly when seeking help from GM Heating and Cooling Inc.
LED Flashing Light Error Codes on Carrier Furnaces
Many Carrier furnaces use LED lights on the control board to indicate status or issues. Here’s a quick guide:
| LED Flash Pattern | What It Indicates |
|---|---|
| Steady OFF | No power or control failure |
| Fast Flashing Yellow | Cooling mode active |
| Slow Flashing Yellow | Call for heat – system heating |
| Steady Red LED 2 | Control board fault |
| Flashing LED 2 | Line voltage reversed or grounding issue |
| LED 3 ON (Yellow) | High heat stage running |
| LED 4 ON (Green) | Low heat stage active |
| Red LED 1 ON | Emergency heat mode |
If your furnace’s lights are flashing in a strange pattern, check the user manual or contact a professional HVAC technician.
What To Do If You See an Error Code
If you spot an error code, follow these steps:
- Turn off the furnace power for safety.
- Note the error code before resetting the system.
- Check the basics – filters, vents, thermostat, and power supply.
- Refer to the user manual for code definitions.
- Try a system reset – sometimes, this resolves temporary glitches.
- Call GM Heating and Cooling Inc. if the code persists or you’re unsure.
When to Call GM Heating and Cooling Inc.
While some issues can be fixed with a filter replacement or reset, others require technical expertise.
Call GM Heating and Cooling Inc. if:
- The same error code appears repeatedly
- There’s no heat despite troubleshooting
- You hear unusual noises or smell gas
- Your furnace won’t turn on at all
- You see signs of electrical or control board issues
GM Heating and Cooling Inc. provides expert Carrier furnace diagnostics, repairs, and maintenance across Canada. Our certified technicians respond promptly and ensure your furnace is running safely and efficiently.
How to Prevent Furnace Error Codes in the First Place
A little maintenance goes a long way when it comes to preventing furnace issues.
Here’s how to avoid future error codes:
- Change air filters every 1–3 months
- Schedule annual maintenance with a professional HVAC company like GM Heating and Cooling Inc.
- Keep vents, registers, and ductwork clean
- Install a programmable thermostat for more consistent heating
- Inspect the exhaust and intake pipes for blockages or snow buildup in winter
- Don’t skip manufacturer-recommended inspections
These steps not only reduce error codes but also improve energy efficiency and extend the life of your furnace.
Are There Any Furnace Rebates in Canada?
Yes! Canada offers several energy-efficiency rebates and incentives when you upgrade or maintain high-efficiency systems:
- Canada Greener Homes Grant – Up to $5,000 for qualified home energy upgrades
- Enbridge Home Efficiency Rebate (Ontario) – Includes rebates on ENERGY STAR® certified furnaces
- BC Hydro and FortisBC Rebates – Vary by location, but often support furnace upgrades
Need help applying for these rebates? GM Heating and Cooling Inc. can assist with the documentation and ensure your upgrades qualify.
Why Choose GM Heating and Cooling Inc.?
At GM Heating and Cooling Inc., we specialize in Carrier furnace service, repair, and installation. When your furnace flashes an error code or stops working, you need fast, affordable, and professional help.
Why Canadian homeowners trust us:
- Licensed & insured HVAC professionals. Same-day repair service
- Emergency furnace repair 24/7
- Transparent pricing
- Expertise in Carrier, Lennox, Goodman, and more
Our goal is to make your home comfortable, no matter the season.
Final Thoughts: Know Your Codes, Stay Warm
So, what do Carrier furnace error codes mean? They’re early warning signs from your system—alerts that something needs attention. While some are simple fixes, others indicate more serious problems.
Understanding these codes helps you act fast, stay safe, and maintain comfort. When in doubt, always trust a certified technician.
GM Heating and Cooling Inc. is here to help Canadian homeowners and businesses keep their furnaces running all winter long.