Rheem furnaces are widely known for their reliability and efficiency in heating homes across America. However, like all heating systems, they may occasionally display fault codes to signal issues needing attention. These fault codes are crucial for homeowners and HVAC professionals to diagnose and address problems quickly. This guide provides an in-depth look at common Rheem furnace fault codes, their meanings, and recommended troubleshooting steps to maintain optimal furnace performance.
| Fault Code | Description | Common Causes | Recommended Action |
|---|---|---|---|
| 1 Flash | Pressure Switch Error | Blocked vent, faulty switch, or wiring problem | Check vent system and replace or repair switch |
| 2 Flashes | Ignition Lockout | Ignitor failure or gas valve problem | Inspect ignitor and gas supply |
| 3 Flashes | Flame Sensing Error | Dirty flame sensor or poor flame sensor positioning | Clean or reposition flame sensor |
| 4 Flashes | Inducer Motor Error | Motor failure or wiring issues | Test inducer motor and connections |
| 5 Flashes | Pressure Switch Remains Open | Vent or inducer issues | Inspect venting and inducer assembly |
What Are Rheem Furnace Fault Codes?
Rheem furnace fault codes are sequences of flashing lights from the furnace control board designed to indicate specific malfunctions. These codes help pinpoint issues such as ignition failures, sensor problems, or motor malfunctions. By recognizing these codes, homeowners and HVAC technicians can perform targeted troubleshooting, facilitating quicker repairs and reducing downtime.
Common Rheem Furnace Fault Codes and Their Meanings
1 Flash – Pressure Switch Error
The furnace cannot detect the pressure switch closing properly, often caused by a blockage in the vent system or a defective pressure switch. This error may also result from wiring faults. Regular maintenance of venting and timely replacement of faulty switches help prevent this issue.
2 Flashes – Ignition Lockout
This code means multiple failed attempts to ignite the burner. Common causes include a malfunctioning ignitor, gas valve problems, or insufficient gas supply. Inspecting the ignitor and ensuring the gas valve operates correctly is crucial to resolving this fault.
3 Flashes – Flame Sensing Error
If the flame sensor does not detect a flame after ignition, the furnace will display this code. This happens due to dirt buildup on the flame sensor rod or misalignment. Cleaning the sensor regularly ensures reliable flame detection and safer operation.
4 Flashes – Inducer Motor Error
This indicates the inducer motor failed to reach the expected speed or is not operating at all. Faulty wiring, motor failure, or a jammed inducer wheel are typical causes. Routine testing and replacement of defective motors restore proper airflow and combustion.
5 Flashes – Pressure Switch Remains Open
The pressure switch does not close after the inducer motor starts, often signaling vent blockages or issues with the inducer assembly. This prevents the furnace from moving to the ignition phase, keeping the system safe. Clearing vent obstructions and inspecting inducer parts are essential steps.
Call 888-906-9139 for Free Local HVAC Quotes – No Obligation, Just Savings!
How to Access Rheem Furnace Fault Codes
To view fault codes, locate the furnace control board where an LED status light is present. During an error, the LED will flash a specific number of times followed by a pause. Counting these flashes helps identify the error. To ensure accuracy, count the flashes several times and reference the Rheem troubleshooting guide for exact code meanings.
Steps for Troubleshooting Rheem Furnace Fault Codes
- Identify the Fault Code: Observe the LED light pattern and note the flash count.
- Consult the Manual: Refer to the furnace’s user manual or official Rheem resources to decode the fault.
- Inspect Components: Examine associated parts such as pressure switches, ignitors, flame sensors, and inducer motors depending on the error.
- Perform Cleaning and Maintenance: Remove debris or dirt, especially from flame sensors and venting systems.
- Test Electrical Connections: Use a multimeter to verify wiring and component functionality.
- Replace Faulty Parts: Replace sensors, switches, or motors if tests indicate failure.
- Reset the Furnace: After repairs, reset the control board to clear the fault codes.
Preventive Measures to Avoid Furnace Fault Codes
- Schedule Annual Maintenance: Professional inspections help catch problems early.
- Keep Vents Clear: Remove obstructions such as debris, nests, or ice.
- Clean Flame Sensors: Regularly clean the sensor rod to prevent false flame sensing errors.
- Ensure Proper Gas Supply: Confirm that gas valves and lines are functioning and unobstructed.
- Monitor Electrical Components: Check wiring and connections for wear or corrosion.
When to Call a Professional HVAC Technician
Although some furnace issues are manageable by homeowners, many require professional expertise. If fault codes persist after basic troubleshooting or if you encounter complex electrical, gas, or mechanical problems, contact a licensed HVAC technician. Professional service ensures safe, efficient repairs aligned with current industry standards and local regulations.
Additional Resources for Rheem Furnace Owners
- Rheem Official Owner Resources – Manuals, troubleshooting guides, and customer support.
- Energy Star Furnace Buying and Maintenance Tips – Guidelines on enhancing furnace efficiency and lifespan.
- ASHRAE HVAC Standards and Practices – Industry standards for HVAC system safety and performance.