u1
Moderate
Mitsubishi Electric · Mini-Splits & Ductless Systems
High Pressure Trip
Quick Answer
Error code U1 on your Mitsubishi Electric Mini-Splits & Ductless Systems means: High Pressure Trip. This is usually fixable — see the step-by-step guide below.
Likely Causes
How to Fix It
1
Clean the outdoor condenser coil with a garden hose spraying from the inside out
2
Verify the outdoor fan motor is operating and the blade is spinning freely
3
Ensure clearance around the outdoor unit meets the minimum installation requirements
4
Check discharge pressure with a gauge manifold and compare to normal operating range
5
A licensed HVAC technician should verify the refrigerant charge and check for non-condensables
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Outdoor fan motor
Fan blade
Coil cleaner
High-pressure switch
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