8 Troubleshooting
Installation and operation manual
18
REMA5+REYA8~20A7Y1B
VRV 5 heat recovery
4P684060-1 – 2022.02
Main code
Contents
De-icing temperature sensor malfunction (outdoor) or
heat exchanger gas temperature sensor malfunction
(outdoor)
Liquid temperature sensor (after subcool HE)
malfunction (outdoor)
Liquid temperature sensor (coil) malfunction (outdoor)
Gas temperature sensor (after subcool HE)
malfunction (outdoor)
High pressure sensor malfunction (S1NPH)
Low pressure sensor malfunction (S1NPL)
INV PCB abnormal
Fin temperature abnormal
INV PCB abnormal
Compressor over current detected
Compressor lock (startup)
Transmission outdoor unit - inverter: INV transmission
trouble
INV unbalanced power supply voltage
Fin thermistor malfunction
Capacity setting malfunction (outdoor)
Abnormal low pressure drop, faulty expansion valve
Reversed power supply phase malfunction
INV voltage power shortage
System test run not yet executed
Faulty wiring indoor/BS unit/outdoor
Abnormal user interface - indoor communication
Faulty wiring to outdoor/outdoor
Warning because there is an error on another unit
(indoor/BS unit)
Connection malfunction over indoor units or type
mismatch
System lock
External ventilation input error
Centralised address duplication
Malfunction in communication centralised control
device - indoor unit
Faulty wiring indoor/BS unit
Auto address malfunction (inconsistency)
(a)
The error code is only shown on the user interface of the indoor
unit where the error occurs.
8.2
Symptoms that are NOT system
malfunctions
The following symptoms are NOT system malfunctions:
8.2.1
Symptom: The system does not operate
▪ The air conditioner does not start immediately after the ON/OFF
button on the user interface is pressed. If the operation lamp
lights, the system is in normal condition. To prevent overloading of
the compressor motor, the air conditioner starts 5 minutes after it
is turned ON again in case it was turned OFF just before. The
same starting delay occurs after the operation mode selector
button was used.
▪ If "Under Centralized Control" is displayed on the user interface,
pressing the operation button causes the display to blink for a few
seconds. The blinking display indicates that the user interface
cannot be used.
▪ The system does not start immediately after the power supply is
turned on. Wait one minute until the micro computer is prepared
for operation.
8.2.2
Symptom: Fan operation is possible, but
cooling and heating do not work
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.
8.2.3
Symptom: The fan speed does not
correspond to the setting
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.
8.2.4
Symptom: The fan direction does not
correspond to the setting
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.
8.2.5
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.
8.2.6
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.
8.2.7
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. A power reset may
help to remove this error.
8.2.8
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.
