Red 3 Flashes, Green 4 Flashes (Single System) — Outdoor Air Sensor Failure

What does Red 3 Flashes, Green 4 Flashes mean?

The red LED flashes three times and the green LED flashes four times on the indoor unit. This indicates a fault with the outdoor ambient air temperature sensor.

• Disconnected or damaged outdoor air sensor.
• Wiring issue affecting the sensor connection.
• Problem with the outdoor unit's electronic controls.

Click steps to track your progress.

1. 1

   Turn off the power to the air conditioner at the circuit breaker.

2. 2

   Wait for one minute, then turn the power back on to reset the system.

3. 3

   Visually inspect the outdoor unit's air intake area for any obstructions.

4. 4

   If the error continues, contact a licensed technician to check the outdoor sensor.