C440 - Prohibit Operation Condition Error (Heating)

What does C440 mean?

This error means the air conditioner cannot operate in heating mode because the outdoor temperature is outside the permissible range. It appears if the outdoor temperature is too high (over 40°C) or too low (under -30°C).

• Outdoor temperature is over 40°C (104°F) while in heating mode.
• Outdoor temperature is under -30°C (-22°F) while in heating mode.
• Extreme environmental conditions preventing safe operation.

Click steps to track your progress.

1. 1

   Turn off the air conditioner at the main power supply for a few minutes.

2. 2

   Check the current temperature around the outdoor unit.

3. 3

   Restore power to the unit and try restarting it.

4. 4

   Wait until the outdoor temperature changes to within the normal operating range.