Rheem Furnace Green Light Blinking 2 Times: What It Means and How to Fix It
When a Rheem furnace’s green light blinks two times, it typically signals a specific diagnostic code indicating an operational issue or maintenance need. This diagnostic feature helps homeowners and technicians quickly identify problems, ensuring the furnace runs safely and efficiently. Understanding what the two blinking green lights mean can prevent furnace breakdowns and improve heating system reliability during cold months.
| Error Code | Number of Blinks | Meaning | Common Solutions |
|---|---|---|---|
| Diagnostic Code 2 | Green Light Blinks Twice | Pressure Switch Problem Or Induced Draft Motor Issue | Check venting, verify pressure switch connections, inspect the draft motor |
What Does a Two-Time Green Light Blink Mean on a Rheem Furnace?
The two blinks of the green light on a Rheem furnace indicate a pressure switch or induced draft motor fault. The pressure switch measures airflow and ensures exhaust gases exit safely through the venting system. If it detects abnormal pressure or airflow, the furnace’s diagnostic system flashes this error to prevent unsafe operation.
Alternatively, issues with the induced draft motor, which helps push exhaust gases out of the heat exchanger, can trigger a similar code. This motor’s failure or obstruction in venting can prevent the furnace from safely starting the ignition sequence.
Common Causes Behind the Two Green Blinks
- Blocked or Restricted Venting: Debris, bird nests, or snow can block vents, causing the pressure switch to detect abnormal pressure.
- Faulty Pressure Switch: A malfunctioning or stuck pressure switch cannot properly measure airflow, leading to the fault code.
- Induced Draft Motor Failure: The motor might have electrical problems or physical obstructions preventing it from operating correctly.
- Wiring Issues: Loose or damaged wires connecting the pressure switch or draft motor disrupt communication with the furnace control board.
- Condensate Drain Blockages: If your Rheem furnace is a high-efficiency model, clogged condensate drains can cause the pressure switch to trip.
Step-By-Step Troubleshooting for the Two Blinking Green Lights
Inspect Furnace Vent and Air Intake
Start by examining the vent pipes outside the home for blockages. Remove any debris, snow, or nests to ensure unrestricted airflow. Verify that the air intake is not clogged or covered. If vent pipes have collapsed sections or disconnected joints, repair or replace them immediately.
Check the Pressure Switch
Locate the pressure switch and examine its tubing for cracks or disconnections. Use a multimeter to test the switch for continuity. If the pressure switch doesn’t open or close properly, replacement is usually necessary.
Evaluate the Induced Draft Motor
Turn off power to the furnace, then manually spin the induced draft motor’s fan wheel to ensure it’s not stuck. Listen for unusual noises when the fan runs. Measurement of voltage should confirm proper motor operation; if faulty, replacement or repair is required.
Inspect Wiring and Connections
Verify all electrical wires connected to the pressure switch and draft motor. Tighten loose connections and replace any frayed or burnt wiring. Ensure the furnace control board is properly connected without corrosion.
Flush and Clear Condensate Drain Lines
If your furnace uses a condensate drain system, clear blockages in the drain lines. Clogged drains can cause pressure switch malfunctions, triggering the two blink code. Regular condensate drain maintenance prevents frequent error codes.
Preventative Maintenance Tips to Avoid Error Codes
- Schedule annual professional furnace inspections and cleanings.
- Keep outdoor vent pipes clear of debris and ice during winter.
- Replace filters regularly to maintain proper airflow inside the furnace.
- Inspect and maintain condensate drains quarterly in high-efficiency models.
- Check electrical connections annually for corrosion or looseness.
When to Call a Professional HVAC Technician
If troubleshooting the blinking green light does not resolve the error, or you are uncomfortable with electrical and mechanical maintenance, contact a certified HVAC technician. Professional diagnosis with specialized tools can accurately pinpoint faults within the furnace’s pressure switch circuitry or draft motor. Attempting repairs without proper knowledge may void warranties or cause unsafe furnace operation.
Additional Information About Rheem Furnace Diagnostic Codes
Rheem furnaces use a system of blinking lights or error codes to communicate issues for easy troubleshooting. Learning these codes can save time and repair costs by addressing minor issues early. The two-blink code in particular is one of the more common indications related to airflow safety mechanisms. Understanding these alerts ensures your furnace remains safe and efficient throughout its service life.