Daikin Error Solution | DAIKIN AC ERROR CODES Daikin Error Solution IN DOOR UNIT A0 -External Security Device Active A1 -indoor unit pcb malfunction A2 ————————————————- – A3 -Drain Level Control System A4 -old protection malfunction A5 -high pressure control in heating, freeze-up safety control in cooling A6 -fan motor malfunction A7 -swing flap motor