E40 — High Pressure Over High Protection

What does E40 mean?

This error indicates that the system's high pressure (Pd) has exceeded 41.5 kg or a critical temperature (Pd_temp) for 5 consecutive minutes. If this occurs 3 times in an hour, the failure will be confirmed as unresumable.

• Overcharge of refrigerant in the system.
• Poor airflow over the outdoor coil (e.g., dirty coil, blocked fan).
• A faulty high pressure sensor or switch.
• Obstruction in the liquid line.

Click steps to track your progress.

1. 1

   Turn off the unit and allow it to cool down and system pressures to normalize.

2. 2

   Inspect the outdoor unit for any obstructions, dirt, or debris blocking the condenser coil or fan.

3. 3

   Ensure the outdoor fan is operating correctly. Clean the outdoor coil if it is dirty.

4. 4

   Restore power and restart the unit. If the error persists or recurs frequently, contact a qualified service technician.