Lennox Error Code F4
Condenser coil temperature sensor fault
Error Code Summary
| Brand | Lennox |
| Error Code | F4 |
| Meaning | Condenser coil temperature sensor fault |
| Cause | Outdoor coil mid-tube thermistor open or short circuit |
| Recommended Action | Check sensor attached to condenser coil, replace if needed |
How to Fix Lennox Error F4
- 1
Power Cycle the Unit
Turn off the unit at the breaker, wait 5 minutes, then restore power. Some errors auto-clear after a restart.
- 2
Identify the Issue
Error F4 means: Condenser coil temperature sensor fault. The most common cause is: Outdoor coil mid-tube thermistor open or short circuit.
- 3
Take Corrective Action
Check sensor attached to condenser coil, replace if needed
- 4
Test the System
After completing repairs, run the system and monitor for the error code. If it recurs, the issue may require professional diagnosis.
Safety Notice
Always disconnect power before performing any electrical work. If you're not a certified HVAC technician, contact a qualified professional for repairs involving refrigerant, electrical components, or compressor work.
Frequently Asked Questions
What does Lennox error code F4 mean?
Lennox error code F4 indicates: Condenser coil temperature sensor fault. This is typically caused by: Outdoor coil mid-tube thermistor open or short circuit.
How do I fix Lennox error code F4?
To fix Lennox error code F4: Check sensor attached to condenser coil, replace if needed. If the error persists after these steps, contact a qualified HVAC technician.
Is Lennox error code F4 serious?
Error code F4 (Condenser coil temperature sensor fault) should be addressed promptly to prevent further damage to your Lennox system. Always turn off the unit if you notice unusual sounds, smells, or continued malfunction.