Lennox Error Code P4
High compressor discharge temperature
Error Code Summary
| Brand | Lennox |
| Error Code | P4 |
| Meaning | High compressor discharge temperature |
| Cause | Discharge line temperature exceeds limit |
| Recommended Action | Check superheat, refrigerant charge, compressor valves |
How to Fix Lennox Error P4
- 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 P4 means: High compressor discharge temperature. The most common cause is: Discharge line temperature exceeds limit.
- 3
Take Corrective Action
Check superheat, refrigerant charge, compressor valves
- 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 P4 mean?
Lennox error code P4 indicates: High compressor discharge temperature. This is typically caused by: Discharge line temperature exceeds limit.
How do I fix Lennox error code P4?
To fix Lennox error code P4: Check superheat, refrigerant charge, compressor valves. If the error persists after these steps, contact a qualified HVAC technician.
Is Lennox error code P4 serious?
Error code P4 (High compressor discharge temperature) 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.