Lennox Error Code 9: Line Voltage Polarity Incorrect
Warning: Your Lennox HVAC system has detected an incorrect line voltage polarity, which could lead to system damage if not addressed.
How to Fix Lennox Code 9
- Step 1: Turn off the power to your HVAC system at the circuit breaker.
- Step 2: Check the wiring connections at the control board and ensure they are properly connected and not reversed.
- Step 3: If you're unsure about any electrical work, contact a professional Lennox technician.
How to Reset Lennox Code 9
- Turn off the furnace power switch, usually located on or near the unit.
- Turn off the circuit breaker for the furnace. Wait 30 seconds.
- Restore power at the breaker and flip the furnace switch back on.
- Set the thermostat to call for heat. If the error code returns after 2-3 ignition attempts, the fault requires repair.
What does 9 mean?
The Lennox 9 error code indicates that the line voltage polarity in your HVAC system is incorrect. This means that the positive and negative wires are reversed, which can cause system malfunctions and potential damage to the components. It's important to have this issue resolved promptly to prevent further problems.
Affected Models
- SLP98V
- SLP98
- EL296V
- EL296
- SLP
- SLP
- ELP
- ELP
- NCB
- NPE
- Elite Series
- Elite Series
- Dave Lennox Signature Collection
- Dave Lennox Signature Collection
- ML195
- SLO
- EL296
- SLP98V
- EL296V
- G61
- ELP
- NCB
- NPE
- NPE
- ML195
- ML199
- Elite Series
- Dave Lennox Signature Collection
- Lennox Healthy Climate
- Elite Series
- Elite Series
- Slimline Series
- Slimline Series
- Health Saver Series
- Pace Series
Replacement Parts
| Part | OEM Number | Est. Cost |
|---|---|---|
| Control Board | 43A101745 | — |
| Wiring Harness | — | — |
Related Codes on Same Models
| Code | Description | Severity |
|---|---|---|
| 1 | Ignition Failure | Warning |
| 2 | Pressure Switch Stuck Closed | Warning |
| 3 | Pressure Switch Stuck Open | Warning |
| 4 | High Limit Switch Open | Warning |
| 5 | Flame Rollout Switch Open | Warning |
| 6 | Pressure Switch System Lockout | Warning |
| 7 | Ignition Lockout | Warning |
| 8 | Control Board Error | Warning |
| E250 | Lennox Code E250 - Indoor Blower Communication Error | Warning |