How much does it cost to fix Daikin error code U2-01?

Typical repair cost for the Daikin U2-01 fault is £80-250 including labour.

U2-01 Low

Daikin U2-01 Fault Code

Q: What does the Daikin U2-01 fault code mean?

Your boiler has detected that the electrical supply coming into the unit is currently too high, which could cause damage to internal parts if left unchecked.

Also written as U201 — same fault.

The Daikin U2-01 fault code means: your boiler has detected that the electrical supply coming into the unit is currently too high, which could cause damage to internal parts if left unchecked.. It appears on 1 Daikin model in our database.

Technical description: Supply voltage is above high limit, your boiler should continue to operate but you need to Contact a heating engineer

What causes the Daikin U2-01 fault?

This fault occurs when the electrical current entering the boiler exceeds the safe operating limits required by the internal electronics. The most common reason is a power surge or a fluctuation in the local grid supply, though it can also be caused by a failing Printed Circuit Board (PCB) that is no longer able to regulate incoming voltage correctly.

Typical repair cost £80-250 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Daikin models that show the U2-01 fault code

Click a model for the full fault code list and model-specific repair notes.

D2CND Repair: £80-250

Source

Daikin U2-01 fault code information on this page is sourced and cross-checked against the official Daikin service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026