Comfortmaker furnaces are widely used in American homes for reliable heating. When issues arise, deciphering Comfortmaker furnace error codes is essential for quick and accurate troubleshooting. These codes help identify specific problems within the system, allowing homeowners or HVAC professionals to take proper corrective action. This article provides a comprehensive guide to common Comfortmaker furnace error codes, their meanings, and actionable steps to resolve them.
| Error Code | Meaning | Suggested Action |
|---|---|---|
| 1 Flash | Pressure switch stuck open or vacuum hose leak | Check and clean pressure switch and hoses; inspect vent pipe |
| 2 Flashes | Pressure switch stuck closed | Inspect switch for damage; ensure proper venting |
| 3 Flashes | Ignition lockout due to repeated failure to ignite | Check ignitor and gas supply; reset system |
| 4 Flashes | Flame sensed when it should not be | Inspect flame sensor; clean or replace as needed |
| 5 Flashes | High limit switch opened | Check airflow; clean filter; verify blower operation |
Common Comfortmaker Furnace Error Codes and What They Indicate
Comfortmaker furnaces use LED flash sequences on their control boards to communicate error codes. Understanding these signals helps in diagnosing problems efficiently.
Pressure Switch Error Codes
The pressure switch ensures proper venting and safe furnace operation. It detects whether exhaust gases are properly vented out of the system.
- 1 Flash – Pressure Switch Stuck Open: This indicates the furnace is not detecting the necessary pressure to start safely. It’s often caused by a blockage or leak in the vent pipe or vacuum hose.
- 2 Flashes – Pressure Switch Stuck Closed: This occurs if the pressure switch remains closed when it should open. This can signal switch failure or venting problems.
Ignition and Flame Sensor Faults
Error codes related to ignition or flame sensing highlight issues within the ignition process or flame detection mechanism.
- 3 Flashes – Ignition Lockout: The furnace attempted multiple ignitions without detecting a flame. This could be due to a faulty ignitor, lack of gas supply, or clogged burners.
- 4 Flashes – Flame Detected When It Shouldn’t Be: A flame is sensed during a stage when the furnace is not firing, which may indicate wiring issues or a malfunctioning flame sensor.
High Limit Switch Issues
The high limit switch acts as a safety device to prevent overheating. Error codes here indicate overheating protection activation.
- 5 Flashes – High Limit Switch Opened: This happens if the furnace overheats, often caused by airflow restriction, dirty filters, or malfunctioning blowers.
How to Locate Error Codes on Comfortmaker Furnaces
Comfortmaker furnaces display error codes through LED lights on the control board, usually located behind the furnace front panel.
- Turn off power to the furnace and remove the front access panel.
- Locate the control board and find the diagnostic LED(s).
- Power the furnace back on while observing the LED flashes.
- Count the flashes and pauses to interpret the error.
Always turn off power before servicing the furnace to ensure safety.
Call 888-906-9139 for Free Local HVAC Quotes – No Obligation, Just Savings!
Troubleshooting Steps Based on Common Error Codes
1 Flash – Pressure Switch Stuck Open
- Inspect vent pipes and chimney for blockages or damage.
- Check vacuum hose for cracks or disconnections.
- Clean the pressure switch with compressed air or replace if faulty.
3 Flashes – Ignition Lockout
- Verify the gas supply to the furnace is turned on and functional.
- Inspect the ignitor for cracks or wear; replace if needed.
- Clean burners to ensure proper ignition.
- Reset the furnace by turning off power for 5 minutes and then back on.
5 Flashes – High Limit Switch Opened
- Replace or clean air filters to improve airflow.
- Inspect blower motor and fan operation.
- Check for duct obstructions or closed vents reducing airflow.
- Ensure thermostat settings are correct to prevent overheating.
Preventive Maintenance to Avoid Furnace Errors
Routine maintenance minimizes furnace errors and improves lifespan.
- Replace air filters regularly, every 1-3 months during heavy use.
- Schedule annual professional furnace inspection and cleaning.
- Keep the area around the furnace clean and free of obstructions.
- Check venting systems seasonally to prevent blockages.
When to Call a Professional HVAC Technician
While some Comfortmaker furnace errors can be resolved by homeowners with basic knowledge, certain situations require professional service.
- Repeated ignition failures after resetting indicate deeper gas or electrical issues.
- Error codes persisting after basic cleaning and checks.
- Unusual noises, smells of gas, or furnace shut off unexpectedly.
- Replacement of parts such as gas valves or control boards.
Consult an experienced HVAC technician to maintain safety and system efficiency.