Daikin Air Conditioner Error U2-00

⚡ Quick Answer: The Daikin air conditioner U2-00 error indicates a communication failure between the indoor and outdoor units, often caused by abnormal power supply v... ✅ DIY Fixable

What Does Error U2-00 Mean?

The Daikin air conditioner U2-00 error indicates a communication failure between the indoor and outdoor units, often caused by abnormal power supply voltage. This may lead to the unit stopping operation, failing to start, or experiencing intermittent functionality. The error can occur after power interruptions or due to unstable voltage levels, requiring immediate attention to prevent further issues.

Common Symptoms:

  • Air conditioner stops operation and displays U2 code
  • Unit fails to start or runs briefly then shuts down
  • Possible lack of cooling/heating function
  • Code appears after power interruption or unstable voltage

Possible Causes

  • Inverter power supply voltage out of range (undervoltage/overvoltage) (high)
  • Unstable or disrupted mains power (e.g., transient interruption, phase loss) (medium)
  • Internal component faults affecting inverter power circuit (e.g., power unit, PCB, contactor, fan motor) (medium)

How to Fix Error U2-00

DIY Fix Check and stabilize power supply

  1. Turn off the air conditioner and disconnect from mains power.
  2. Ensure the supply voltage to the unit is within the normal operating range.
  3. Confirm there was no recent power surge or outage that could have triggered the code.

DIY Fix Restart the air conditioner

  1. Switch off the air conditioner at the breaker or unplug it.
  2. Wait at least 1–5 minutes.
  3. Restore power and attempt to restart the unit to see if the error clears.

Technician Only Inspect and repair internal power components

  1. Measure incoming supply voltage under load to confirm stability.
  2. Check inverter power unit, contactors, and PCB for faults or damage.
  3. Test fan motor and other related components for proper operation.
  4. Replace defective power conversion/control parts as identified.

Parts needed: Inverter power unit, Main PCB / control board, Contactors, Fan motor

🛑 When to Call a Pro:
  • If error persists after power stabilization and restart
  • If there are signs of electrical damage, burning smell, or repeated faults
  • If supply voltage is stable but the unit still shows U2

Next step

Choose the next step for U2-00

Confirm the diagnosis before ordering. An error code can identify the system involved, but it does not prove that a specific part has failed.

Based on diagnostic data

Most relevant component to inspect

HVAC Control Board

Controls fan, compressor, sensor, and communication functions in the HVAC unit.

Typical part-only price
$90 - $320
DIY difficulty
Hard
Estimated time
45-120 mins
Where can I find the model number?

Check the rating label around the door, lid, frame, rear panel, or inside the appliance cabinet. Use the complete model number, including suffixes.

Find a part that fits my model

Verify the complete model and part number on the retailer's compatibility page before ordering.

Other parts options

Check related components first; use model search as a fallback.

Model number required

Model-compatible Air Conditioner parts

Enter the complete model number to browse compatible replacement parts. This is a model-based parts search, not a diagnosis that a specific component failed.

Find a part that fits my model

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Optional routine care

Maintenance supplies

These products support cleaning or routine upkeep. They are separate from the possible repair components above and are not claimed to fix this error code or symptom.

Maintenance supply

Air Conditioner Fin Cleaner

For routine cleaning of accessible coil fins when permitted by the manufacturer. Disconnect power and follow product and appliance instructions.

View maintenance supply
Maintenance supply

Model-Compatible Washable AC Filter

A reusable filter option only where the appliance supports one. Match the full model, dimensions, and filter specification.

Compatibility check required: use the complete appliance model and compare the existing filter, bag, or specification before ordering.

Find one that fits my model

Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases. Recommendations are based on routine-care relevance, not commission rate.

Technical Specifications

wattage N/A
component Control Board
resistance N/A
part_number DAIKIN 4E-1000
voltage_rating 220V AC

Common Questions

What does U2-00 error mean on daikin air conditioner?

The U2-00 error indicates a communication failure between indoor and outdoor units, often due to power supply issues.

Can I fix daikin air conditioner U2-00 error myself?

Yes, check and stabilize the power supply, then restart the unit to see if the error clears.

How much does it cost to fix U2-00 error?

Repair costs vary widely based on model and parts, typically medium to high depending on the failure.

When should I call a technician for U2-00?

Call a technician if the error persists after troubleshooting or if you notice electrical damage or repeated faults.

Data last verified: 2026-07-25

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