Error 428 — Compressor operation stop due to abnormal compression ratio

What does 428 mean?

The compressor has stopped because the ratio between its discharge and suction pressures is abnormal. This suggests an internal issue with the compressor or refrigerant circuit.

• Internal compressor fault
• Severe refrigerant flow restriction
• Incorrect system pressures
• Faulty pressure sensors

Click steps to track your progress.

1. 1

   Check refrigerant pressures (high and low side) with appropriate gauges.

2. 2

   Inspect the refrigerant circuit for any blockages or restrictions.

3. 3

   Verify the operation of pressure sensors.

4. 4

   This error typically requires a technician to diagnose the compressor itself.