SiBE121021_C Problem Symptoms and Measures
Service Diagnosis 289
2. Problem Symptoms and Measures
Problem Symptom Check Item Details of Measure
Reference
Page
None of the units operates. Check the power supply. Check if the rated voltage is supplied. —
Check the type of the indoor units. Check if the indoor unit type is compatible with
the outdoor unit.
—
Check the outdoor temperature. Heating operation cannot be used when the
outdoor temperature is 20°C or higher, and
cooling operation cannot be used when the
outdoor temperature is below –10 ~ 10°C
(depending on the model).
—
Diagnose with remote controller
indication
— 306, 307
Check the remote controller
addresses.
Check if address settings for the remote
controller and indoor unit are correct.
447
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 20°C or higher, and
cooling operation cannot be used when the
outdoor temperature is below –10 ~ 10°C
(depending on the model).
—
Diagnose with remote controller
indication.
— 306, 307
Some indoor units do not
operate.
Check the type of the indoor units. Check if the indoor unit type is compatible with
the outdoor unit.
—
Diagnose with remote controller
indication
— 306, 307
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 if 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 if the each electronic expansion valve
works.
—
Diagnose with remote controller
indication.
— 306, 307
Diagnose by service port pressure
and operating current.
Check for refrigerant shortage. 357
Large operating noise and
vibrations
Check the output voltage of the
power module.
—369
Check the power module. — —
Check the installation condition. Check if the required spaces for installation
(specified in the installation manual, etc.) are
provided.
—