U1
Mitsubishi Heavy
Mitsubishi Heavy air conditioner error U1
Meaning
Abnormal high pressure (High pressure switch 63H worked)
General meaning for the brand's models, unless a model's own manual says otherwise.
Causes and how to check
- the cited manual page, and follow-up questions
No account needed to look up codes.
Guides
- Pressure, low refrigerant and high discharge temperature errors: where to start
Pressure and discharge-temperature protection codes: tell a low charge from a blockage or poor heat rejection before charging.