Symptom: Fan Operation Is Possible, But Cooling And Heating Do Not Work; Symptom: The Fan Speed Does Not Correspond To The Setting; Symptom: The Fan Direction Does Not Correspond To The Setting; Symptom: White Mist Comes Out Of A Unit (Indoor Unit) - Daikin VRV IV W+ Series Installer And User Reference Manual

11 | Troubleshooting

11.2.3 Symptom: Fan operation is possible, but cooling and heating do not work

11.2.4 Symptom: The fan speed does not correspond to the setting

11.2.5 Symptom: The fan direction does not correspond to the setting

11.2.6 Symptom: White mist comes out of a unit (Indoor unit)

11.2.7 Symptom: White mist comes out of a unit (Indoor unit, outdoor unit)

11.2.8 Symptom: The user interface reads "U4" or "U5" and stops, but then restarts after a few
minutes

11.2.9 Symptom: Noise of air conditioners (Indoor unit)

Installer and user reference guide
40
▪ When the cool/heat changeover remote control switch is installed and the
display shows (change-over under centralized control), this is because cool/
heat changeover is controlled by the cool/ heat changeover remote control
switch. Ask your dealer where the remote control switch is installed.
Immediately after the power is turned on. The micro computer is getting ready to
operate and is performing a communication check with all indoor units. Please wait
12 minutes maximally until this process is finished.
The fan speed does not change even if the fan speed adjustment button is pressed.
During heating operation, when the room temperature reaches the set
temperature, the outdoor unit goes off and the indoor unit changes to whisper fan
speed. This is to prevent cold air blowing directly on occupants of the room. The
fan speed will not change even when another indoor unit is in heating operation, if
the button is pressed.
The fan direction does not correspond with the user interface display. The fan
direction does not swing. This is because the unit is being controlled by the micro
computer.
▪ When humidity is high during cooling operation. If the interior of an indoor unit is
extremely contaminated, the temperature distribution inside a room becomes
uneven. It is necessary to clean the interior of the indoor unit. Ask your dealer for
details on cleaning the unit. This operation requires a qualified service person.
▪ Immediately after the cooling operation stops and if the room temperature and
humidity are low. This is because warm refrigerant gas flows back into the indoor
unit and generates steam.
When the system is changed over to heating operation after defrost operation.
Moisture generated by defrost becomes steam and is exhausted.
This is because the user interface is intercepting noise from electric appliances
other than the air conditioner. The noise prevents communication between the
units, causing them to stop. Operation automatically restarts when the noise
ceases.
▪ A "zeen" sound is heard immediately after the power supply is turned on. The
electronic expansion valve inside an indoor unit starts working and makes the
noise. Its volume will reduce in about one minute.
RWEYQ8~14T9Y1B
VRV IV water-cooled system air conditioner
4P452191-1B – 2020.10