E221, E231, E251, E320 — Outdoor Unit Sensor Error

What does E221, E231, E251, E320 mean?

These codes indicate a problem with one of the temperature or pressure sensors in the outdoor unit. E221 relates to the outdoor unit temperature sensor, E231 to the condenser (COND.) sensor, E251 to the discharge sensor, and E320 to the OLP sensor.

• Loose or disconnected sensor connector.
• Faulty temperature sensor.
• Problem with the outdoor unit's main control board.

Click steps to track your progress.

1. 1

   Turn off the air conditioner at the main power switch or circuit breaker.

2. 2

   Locate the outdoor unit. Inspect the temperature sensor connectors for any loose or disconnected wires (specific connector numbers like CN43, CN501, CN502 are mentioned in the manual, but generally check all accessible sensor connections).

3. 3

   Reconnect any sensor wires that are loose or disconnected.

4. 4

   Turn the power back on and check if the error is resolved.

5. 5

   If the error returns, contact customer support, as a sensor or main control board may need to be checked by a technician.