U2 - Abnormal high discharging temperature or inner thermostat (49C) operation in outdoor unit

What does U2 mean?

This error indicates that the outdoor unit is experiencing an abnormally high discharge temperature, or the inner thermostat (49C) has activated as a safety measure.

• Insufficient refrigerant charge (low refrigerant).
• Dirty outdoor coil restricting airflow.
• Malfunctioning outdoor fan.
• Clogged or restricted refrigerant lines.
• Faulty discharge temperature sensor or inner thermostat.

Click steps to track your progress.

1. 1

   Check the outdoor unit for any obstructions blocking airflow to the coil. Clear any debris.

2. 2

   Ensure the outdoor fan is running freely and not obstructed.

3. 3

   Turn off the unit at the circuit breaker, wait 30 seconds, and turn it back on to reset.

4. 4

   If the problem persists, contact a qualified HVAC technician to check refrigerant levels and sensor operation.