Symptom: White Mist Comes Out Of A Unit (Indoor Unit); Symptom: White Mist Comes Out Of A Unit (Indoor Unit, Outdoor Unit); Symptom: The User Interface Reads "U4" Or "U5" And Stops, But Then Restarts After A Few Minutes; Symptom: Noise Of Air Conditioners (Indoor Unit) - Daikin RXYLQ10T7Y1B Series Installation And Operation Manual

9 Relocation

8.2.6 Symptom: White mist comes out of a unit
(Indoor unit)
▪ When humidity is high during cooling operation. If the interior of an
indoor unit 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.
8.2.7 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.
8.2.8 Symptom: The user interface reads "U4"
or "U5" and stops, but then restarts after a
few minutes
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.
8.2.9 Symptom: Noise of air conditioners
(Indoor unit)
▪ 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.
▪ A continuous low "shah" sound is heard when the system is in
cooling operation or at a stop. When the drain pump (optional
accessories) is in operation, this noise is heard.
▪ A "pishi-pishi" squeaking sound is heard when the system stops
after heating operation. Expansion and contraction of plastic parts
caused by temperature change make this noise.
▪ A low "sah", "choro-choro" sound is heard while the indoor unit is
stopped. When another indoor unit is in operation, this noise is
heard. In order to prevent oil and refrigerant from remaining in the
system, a small amount of refrigerant is kept flowing.
8.2.10 Symptom: Noise of air conditioners
(Indoor unit, outdoor unit)
▪ A continuous low hissing sound is heard when the system is in
cooling or defrost operation. This is the sound of refrigerant gas
flowing through both indoor and outdoor units.
▪ A hissing sound which is heard at the start or immediately after
stopping operation or defrost operation. This is the noise of
refrigerant caused by flow stop or flow change.
8.2.11 Symptom: Noise of air conditioners

(Outdoor unit)

When the tone of operating noise changes. This noise is caused by
the change of frequency.
Installation and operation manual
14
8.2.12

Symptom: Dust comes out of the unit

When the unit is used for the first time in a long time. This is
because dust has gotten into the unit.
8.2.13

Symptom: The units can give off odours

The unit can absorb the smell of rooms, furniture, cigarettes, etc.,
and then emit it again.
8.2.14 Symptom: The outdoor unit fan does not
spin
During operation. The speed of the fan is controlled in order to
optimise product operation.
8.2.15

Symptom: The display shows "88"

This is the case immediately after the main power supply switch is
turned on and means that the user interface is in normal condition.
This continues for 1 minute.
8.2.16 Symptom: The compressor in the outdoor
unit does not stop after a short heating
operation
This is to prevent refrigerant from remaining in the compressor. The
unit will stop after 5 to 10 minutes.
8.2.17 Symptom: The inside of an outdoor unit is
warm even when the unit has stopped
This is because the crankcase heater is warming the compressor so
that the compressor can start smoothly.
8.2.18 Symptom: Hot air can be felt when the
indoor unit is stopped
Several different indoor units are being run on the same system.
When another unit is running, some refrigerant will still flow through
the unit.
9 Relocation
Contact your dealer for removing and reinstalling the total unit.
Moving units requires technical expertise.
10

Disposal

This unit uses hydrofluorocarbon. Contact your dealer when
discarding this unit.
NOTICE
Do NOT try to dismantle the system yourself: dismantling
of the system, treatment of the refrigerant, oil and other
parts MUST comply with applicable legislation. Units
MUST be treated at a specialised treatment facility for
reuse, recycling and recovery.
RXMLQ8 + RXYLQ10~14T7Y1B*
VRV IV system air conditioner
4P543426-1B – 2020.10