E251 (Red ON, Green Blink, Yellow OFF) — Discharge temperature sensor error

What does E251 mean?

The outdoor unit's PCB LED displays E251 when an open or short circuit is detected in the compressor's discharge temperature sensor. This sensor helps protect the compressor from overheating.

• Damaged discharge temperature sensor
• Loose or faulty sensor wiring connection
• Faulty outdoor PCB

Click steps to track your progress.

1. 1

   Turn off the main power to the outdoor unit at the circuit breaker.

2. 2

   Visually inspect the discharge temperature sensor and its wiring for any signs of damage or loose connections.

3. 3

   Ensure the sensor is securely attached to the compressor discharge line.

4. 4

   Restore power to the unit. If the error persists, contact a qualified technician to test or replace the sensor.