Lennox Error Code F5
Discharge temperature sensor fault
Error Code Summary
| Brand | Lennox |
| Error Code | F5 |
| Meaning | Discharge temperature sensor fault |
| Cause | Compressor discharge thermistor open or short circuit |
| Recommended Action | Inspect sensor on discharge line, replace if faulty |
How to Fix Lennox Error F5
- 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 F5 means: Discharge temperature sensor fault. The most common cause is: Compressor discharge thermistor open or short circuit.
- 3
Take Corrective Action
Inspect sensor on discharge line, replace if faulty
- 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 F5 mean?
Lennox error code F5 indicates: Discharge temperature sensor fault. This is typically caused by: Compressor discharge thermistor open or short circuit.
How do I fix Lennox error code F5?
To fix Lennox error code F5: Inspect sensor on discharge line, replace if faulty. If the error persists after these steps, contact a qualified HVAC technician.
Is Lennox error code F5 serious?
Error code F5 (Discharge 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.