Daikin Error Code Library

Complete Daikin HVAC Error Reference

Air Conditioner Error Codes

A1

Indoor PCB failure

A3

Drain system malfunction

A6

Fan motor error

C4

Heat exchanger sensor fault

C7

Louver motor failure

E1

Outdoor PCB failure

E5

Compressor overload

E6

Compressor startup failure

E7

Outdoor fan motor fault

E9

Electronic expansion valve error

Heat Pump Error Codes

U0

Low refrigerant level

U2

Power supply voltage issue

U4

Signal transmission error

U5

Communication error indoor/outdoor

System Messages

DEFROST

Defrost cycle active

LOCK

Control lock enabled

RESET

System restart required

OVERHEAT

Overheat protection triggered

FILTER

Air filter needs cleaning

STANDBY

Unit in standby mode