What does 3 mean?
Discharge pressure exceeded 590 PSI (R-410A) protection threshold.
Common causes
- Dirty condenser coil reducing heat rejection
- Failed or backward condenser fan motor
- Refrigerant overcharge
- Refrigerant restriction in liquid line
- High ambient temperature above unit rating
Diagnostic & testing steps
- 1. Measure discharge pressure with manifold gauges
- 2. Clean condenser coil - flush with coil cleaner from inside out
- 3. Verify condenser fan spins correct direction (top discharge)
- 4. Test condenser fan capacitor
- 5. Check subcooling: overcharge if >20°F subcooling
Tools required
- Manifold gauges
- Capacitor tester
- Coil cleaner
- Garden hose
OEM parts & part numbers
Condenser Fan Motor, Fan Capacitor, Condenser Coil
Part numbers: MOT09025, CPT00449, BAYEV1A24
Safety warning
⚠️ System under extreme pressure when faulted. Do not open refrigerant circuit without proper training.
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