U2

Abnormal Discharge Temperature / Insufficient Refrigerant

Description

The compressor discharge temperature is abnormally high, usually caused by a refrigerant leak, insufficient refrigerant charge, or a blocked refrigerant circuit.

Appliance Error Codes Details

Error Code
U2
Error Name
Abnormal Discharge Temperature / Insufficient Refrigerant
Appliance Type
air_conditioner
Brand
Mitsubishi
Severity
high

Additional Troubleshooting

1. Turn off the unit
2. Check that the stop (service) valves are fully open
3. Do not attempt DIY refrigerant work
4. Contact a licensed technician to check for leaks and verify the refrigerant charge

Was this helpful?

Loading...

Send Feedback

Found an error or have a suggestion? We respond within 48 hours.

About this page

Author: Pavel Volkov
Created:

Learn More

Dive deeper with our comprehensive developer guides for Appliance Error Codes

Appliance Error Codes: Troubleshooting Guide

Fix your home appliances with our comprehensive troubleshooting guide. Learn to identify error codes...

Pavel Volkov Aug 30, 2025
View all guides

Related Codes

More codes of the same type

P9

Pipe Temperature Sensor Error (TH5)

The condenser/evaporator pipe temperature sensor (TH5) has an open or short circ...

View details →

Pb

Indoor Fan Motor Error

The indoor unit's fan motor is not responding correctly or is drawing abnormal c...

View details →

PL

Refrigerant Circuit Abnormality

The system has detected an abnormal condition in the refrigerant circuit, typica...

View details →

U1

Abnormal High Pressure (63H Tripped)

The outdoor unit's high-pressure switch (63H) has tripped due to excessive refri...

View details →

U4

Outdoor Thermistor Open/Short Circuit

One of the outdoor unit's temperature thermistors has an open or short circuit,...

View details →

U6

Compressor Overcurrent

The compressor is drawing too much current.

View details →

U8

Outdoor Fan Motor Protection Stop

The outdoor unit's fan motor has stopped due to abnormal rotation speed, often c...

View details →

UF

Compressor Overcurrent (Locked Rotor)

The compressor drew excessive current because its rotor is locked (unable to tur...

View details →
Back to Appliance Error Codes