Specifications

Problem Symptoms and Measures SiUS12-928_A
93 Service Diagnosis
2. Problem Symptoms and Measures
Symptom Check Item Details of Measure Reference
Page
None of the units operates. Check the power supply. Check to make sure that the rated voltage is
supplied.
—
Check the type of the indoor units. Check to make sure that the indoor unit type is
compatible with the outdoor unit.
—
Check the outdoor temperature. Heating operation cannot be used when the
outdoor temperature is 15.5°C (59.9°F) or
higher, and cooling operation cannot be used
when the outdoor temperature is below
–10°C (14°F).
—
Diagnose with outdoor unit LED
indication
— 102
Check the remote controller
addresses.
Check to make sure that address settings for
the remote controller and indoor unit are
correct.
223
Operation sometimes
stops.
Check the power supply. A power failure of 2 to 10 cycles can stop air
conditioner operation. (Operation lamp OFF)
—
Check the outdoor temperature. Heating operation cannot be used when the
outdoor temperature is 15.5°C (59.9°F) or
higher, and cooling operation cannot be used
when the outdoor temperature is below
–10°C (14°F).
—
Diagnose with outdoor unit LED
indication.
— 102
Some indoor units do not
operate.
Check the type of the indoor units. Check to make sure that the indoor unit type is
compatible with the outdoor unit.
—
Diagnose with outdoor unit LED
indication
— 102
Units operate but do not
cool, or do not heat.
Check for wiring and piping errors in
the connection between the indoor
and outdoor units.
Conduct the wiring/piping error check described
on the product diagnosis nameplate.
—
Check for thermistor detection errors. Check to make sure that the thermistor is
mounted securely.
—
Check for faulty operation of the
electronic expansion valve.
Set all the units to cooling operation, and
compare the temperatures of the liquid pipes to
see the each electronic expansion valve works.
—
Diagnose with outdoor unit LED
indication.
— 102
Diagnose by service port pressure
and operating current
Check for refrigerant shortage. 143
Large operating noise and
vibrations
Check the output voltage of the
power transistor.
— 156
Check the power transistor. — —
Check the installation condition. Check to make sure that the required spaces
for installation (specified in the installation
manual, etc.) are provided.
—