Daikin VRV IV W+ Series Installer And User Reference Manual

Also see for RWEYQ10T9Y1B: Installer and user guide Installation and operation manual Installation and operation manual

11 | TroubleshootingInstaller and user reference guide40RWEYQ8~14T9Y1BVRV IV water-cooled system air conditioner4P452191-1B – 2020.10▪ When the cool/heat changeover remote control switch is installed and thedisplay shows (change-over under centralized control), this is because cool/heat changeover is controlled by the cool/ heat changeover remote controlswitch. Ask your dealer where the remote control switch is installed.11.2.3 Symptom: Fan operation is possible, but cooling and heating do not workImmediately after the power is turned on. The micro computer is getting ready tooperate and is performing a communication check with all indoor units. Please wait12 minutes maximally until this process is finished.11.2.4 Symptom: The fan speed does not correspond to the settingThe fan speed does not change even if the fan speed adjustment button is pressed.During heating operation, when the room temperature reaches the settemperature, the outdoor unit goes off and the indoor unit changes to whisper fanspeed. This is to prevent cold air blowing directly on occupants of the room. Thefan speed will not change even when another indoor unit is in heating operation, ifthe button is pressed.11.2.5 Symptom: The fan direction does not correspond to the settingThe fan direction does not correspond with the user interface display. The fandirection does not swing. This is because the unit is being controlled by the microcomputer.11.2.6 Symptom: White mist comes out of a unit (Indoor unit)▪ When humidity is high during cooling operation. If the interior of an indoor unit isextremely contaminated, the temperature distribution inside a room becomesuneven. It is necessary to clean the interior of the indoor unit. Ask your dealer fordetails on cleaning the unit. This operation requires a qualified service person.▪ Immediately after the cooling operation stops and if the room temperature andhumidity are low. This is because warm refrigerant gas flows back into the indoorunit and generates steam.11.2.7 Symptom: White mist comes out of a unit (Indoor unit, outdoor unit)When the system is changed over to heating operation after defrost operation.Moisture generated by defrost becomes steam and is exhausted.11.2.8 Symptom: The user interface reads "U4" or "U5" and stops, but then restarts after a fewminutesThis is because the user interface is intercepting noise from electric appliancesother than the air conditioner. The noise prevents communication between theunits, causing them to stop. Operation automatically restarts when the noiseceases.11.2.9 Symptom: Noise of air conditioners (Indoor unit)▪ A "zeen" sound is heard immediately after the power supply is turned on. Theelectronic expansion valve inside an indoor unit starts working and makes thenoise. Its volume will reduce in about one minute.