u2
Easy Fix
Daikin · Mini-Splits & Ductless Systems
Power Supply Voltage Abnormal
Quick Answer
Error code U2 on your Daikin Mini-Splits & Ductless Systems means: Power Supply Voltage Abnormal. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
Likely Causes
How to Fix It
1
Measure voltage at the outdoor unit disconnect under load and at no load
2
Compare measured voltage to the unit's rated operating range (typically 187-253VAC for 230V units)
3
Check all connections at the disconnect switch and outdoor unit terminal block for tightness
4
Verify wire gauge is adequate for the circuit length and unit amperage rating
5
Contact a licensed electrician if voltage is consistently outside the acceptable range
Pro Tip
This is a common issue that most users can resolve without specialized tools. Try the first step before moving on to more complex solutions.
Parts You May Need
Disconnect switch (if faulty)
Electrical wire (correct gauge)
Circuit breaker
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