Daikin Heat Pump Error Codes

Complete Daikin Heat Pump Guide

This guide explains all Daikin Heat Pump error codes (CH series) with simple troubleshooting steps to help you identify and fix common issues safely before calling a technician.

U0
Low Refrigerant Level
  • Check the system for refrigerant leaks.
  • Inspect pressure levels using proper HVAC gauges.
  • Repair and seal leaks before recharging.
  • Call a certified technician for safe refrigerant handling.
U2
Power Supply Voltage Issue
  • Check incoming voltage stability.
  • Inspect circuit breakers and electrical wiring.
  • Ensure correct power supply rating for the unit.
  • Use a voltage stabilizer if fluctuations persist.
U4
Signal Transmission Error
  • Inspect wiring between control boards.
  • Check connectors for looseness or corrosion.
  • Reset the system after inspection.
  • Replace damaged communication cables if needed.
U5
Indoor/Outdoor Communication Error
  • Verify connection between indoor and outdoor units.
  • Inspect wiring for damage or disconnection.
  • Restart both units to reset communication.
  • Replace control board if the issue persists.
A1
Indoor PCB Failure
  • Turn off power supply immediately.
  • Inspect indoor control board connections.
  • Check for burnt or damaged components.
  • Replace PCB if malfunction continues.
A3
Drain System Malfunction
  • Check drain hose for blockage.
  • Clean condensate pan and drainage pipe.
  • Ensure proper water flow through system.
  • Remove any debris in drainage path.
A6
Fan Motor Error
  • Inspect indoor fan motor for obstruction.
  • Check wiring and electrical connectors.
  • Clean dust buildup on fan blades.
  • Replace motor if it fails to operate.
C4
Heat Exchanger Sensor Fault
  • Check temperature sensor connection.
  • Inspect sensor for corrosion or damage.
  • Replace thermistor if readings are inaccurate.
  • Secure wiring to ensure stable signal.
C7
Louver Motor Failure
  • Check louver movement for obstruction.
  • Inspect motor wiring and gear assembly.
  • Reset system and test swing function.
  • Replace motor if it does not respond.
E1
Outdoor PCB Failure
  • Turn off power before inspection.
  • Inspect outdoor control board connections.
  • Check for burnt or damaged components.
  • Replace PCB if fault continues.
E5
Compressor Overload
  • Allow compressor to cool down.
  • Check refrigerant charge and balance.
  • Inspect condenser airflow for blockage.
  • Call technician if overload persists.
E6
Compressor Startup Failure
  • Check power supply stability.
  • Inspect capacitor and wiring connections.
  • Ensure compressor is not mechanically seized.
  • Service unit if startup repeatedly fails.
E7
Outdoor Fan Motor Fault
  • Check fan blades for obstruction.
  • Inspect motor wiring connections.
  • Clean dust and debris from fan assembly.
  • Replace motor if defective.
E9
Electronic Expansion Valve Error
  • Check valve control wiring.
  • Inspect refrigerant flow system.
  • Reset system and retest operation.
  • Replace valve if malfunction persists.
F3
Discharge Temperature Abnormal
  • Check refrigerant level and charge condition.
  • Inspect compressor performance.
  • Ensure proper airflow across condenser.
  • Service system if overheating continues.
H6
Compressor Lock Protection
  • Check compressor for mechanical seizure.
  • Inspect capacitor and start components.
  • Verify stable voltage supply.
  • Replace compressor if locked.
P4
High Pressure Protection
  • Clean condenser coils and filters.
  • Check airflow obstruction.
  • Inspect for refrigerant overcharge.
  • Reduce system load and restart.
J3
Discharge Pipe Temperature Fault
  • Check discharge temperature sensor.
  • Inspect refrigerant flow and compressor load.
  • Clean condenser coils.
  • Service system if overheating persists.
DAI-HP21
Heating Mode Not Working
  • Check heating mode is selected.
  • Set temperature higher than room temperature.
  • Clean air filters for better airflow.
  • Inspect outdoor unit for ice or blockage.
DAI-HP22
Cooling Mode Not Working
  • Confirm cooling mode is selected.
  • Check thermostat settings.
  • Clean filters and indoor unit.
  • Inspect refrigerant level if performance is weak.
DAI-HP23
Unusual Noise From Heat Pump
  • Check for loose panels or mounting issues.
  • Clean fan blades and remove debris.
  • Inspect outdoor unit obstruction.
  • Call technician if compressor noise persists.
DAI-HP24
Heat Pump Turning Off Unexpectedly
  • Check timers and thermostat settings.
  • Inspect power supply and breaker.
  • Clean filters to prevent overheating.
  • Check for system error codes.
DAI-HP25
Water Leakage From Unit
  • Check drain line for blockage.
  • Inspect for ice buildup.
  • Ensure proper installation and leveling.
  • Clean air filters regularly.
DAI-HP26
Cold Air in Heating Mode
  • Check defrost cycle operation.
  • Ensure heating mode is active.
  • Inspect outdoor unit frost buildup.
  • Allow system time to stabilize.
DAI-HP27
Remote Control Not Responding
  • Replace remote batteries.
  • Check sensor alignment.
  • Remove obstacles between remote and unit.
  • Reset system if needed.
DAI-HP28
Outdoor Unit Frozen / Ice Build-Up
  • Check defrost cycle operation.
  • Ensure proper airflow around unit.
  • Inspect outdoor unit for ice buildup.
  • Call technician if freezing persists.
DAI-HP29
Low Efficiency Performance
  • Clean or replace filters.
  • Close doors and windows.
  • Check correct unit sizing.
  • Inspect refrigerant levels.
DAI-HP30
System Reset Procedure
  • Turn off power or breaker.
  • Wait 5–10 minutes.
  • Restart system.
  • Restore default settings if needed.

Frequently Asked Questions


What does DAI-HP01 Device Not Detected mean?
Check power supply, ensure the Daikin heat pump is turned on, verify remote control batteries, and restart the system.
What does DAI-HP02 No Heating/Cooling Output mean?
Check thermostat settings, select correct heating or cooling mode, clean air filters, and inspect refrigerant level if performance is weak.
What does DAI-HP03 Weak Airflow mean?
Clean air filters, remove dust buildup, check fan operation, and ensure vents and indoor/outdoor units are not blocked.
What does DAI-HP04 Water Leakage mean?
Check condensate drain line for blockage, clean drain pan, ensure proper installation level, and inspect for ice buildup.
What does DAI-HP05 Loud Noise From Unit mean?
Check for loose panels, clean fan blades, remove debris, and inspect compressor or motor if noise continues.
What does DAI-HP06 Heat Pump Not Turning On mean?
Check power supply and circuit breaker, replace remote batteries, ensure wiring is secure, and reset the system.
What does DAI-HP07 Remote Not Working mean?
Replace batteries, ensure no obstruction to IR sensor, clean sensor area, and try manual or wall controller operation.
What does DAI-HP08 System Turns Off Automatically mean?
Check timer settings, inspect power stability, clean filters to prevent overheating, and reset the heat pump.
What does DAI-HP09 Not Responding to Controls mean?
Replace batteries, check indoor receiver, restart the heat pump, and ensure controller compatibility.
What does DAI-HP10 System Reset Required mean?
Turn off the unit, disconnect power for 5–10 minutes, restart system, and restore default settings if needed.
What does DAI-HP11 Weak Heating/Cooling at Night mean?
Check temperature settings, clean filters, ensure proper airflow, and close doors and windows to improve efficiency.
What does DAI-HP12 Bad Odor From Heat Pump mean?
Clean indoor unit and filters, remove moisture buildup, run fan mode regularly, and check drainage system.
What does DAI-HP13 Ice Formation on Unit mean?
Check airflow, clean filters, inspect refrigerant levels, and allow unit to complete defrost cycle before restarting.
What does DAI-HP14 Outdoor Unit Not Working mean?
Check power connection, inspect compressor operation, ensure correct voltage, and call technician if needed.
What does DAI-HP15 Electrical Trip Issue mean?
Check wiring, inspect circuit breaker, avoid overloaded circuits, and ensure stable power supply.
What does DAI-HP16 Error Display on Heat Pump mean?
Restart system, check error code reference guide, clean filters, and contact service if the error persists.
What does DAI-HP17 Heat Pump Not Blowing Warm Air mean?
Check heating mode, clean filters, inspect refrigerant level, and ensure compressor and outdoor unit are operating.
What does DAI-HP18 Strange Odor in Room mean?
Clean indoor unit, replace filters, check drainage system, and run ventilation mode to clear odors.
What does DAI-HP19 Indoor Unit Not Receiving Signal mean?
Check remote batteries, ensure IR sensor is clean, restart system, and remove obstructions between controller and unit.
What does DAI-HP20 Maintenance Required mean?
Clean filters, inspect coils, check airflow system, and schedule professional maintenance if needed.
Important: Always disconnect power before performing repairs. Contact a qualified technician if the issue persists.