Service Manual

SiUS091133 Problem Symptoms and Measures
Service Diagnosis 90
2. Problem Symptoms and Measures
Symptom Check Item Details of Measure Reference
Page
The unit does not operate. Check the power supply. Check if the rated voltage is supplied. —
Check the type of the indoor unit. 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 24°C (75.2°F) or higher,
and cooling operation cannot be used when the
outdoor temperature is below 10°C (50°F).
—
Diagnose with remote controller
indication.
—
94
Check the remote controller
addresses.
Check if address settings for the remote
controller and indoor unit are correct.
388
Operation sometimes
stops.
Check the power supply. A power failure of 2 to 10 cycles stops air
conditioner operation. (Operation lamp OFF)
—
Check the outdoor temperature. Heating operation cannot be used when the
outdoor temperature is 24°C (75.2°F) or higher,
and cooling operation cannot be used when the
outdoor temperature is below 10°C (50°F).
—
Diagnose with remote controller
indication.
—
94
The unit operates but does
not cool, or does not heat.
Check for wiring and piping errors in
the connection between the indoor
unit and outdoor unit.
—
—
Check for thermistor detection errors. Check if the thermistor is mounted securely. —
Check for faulty operation of the
electronic expansion valve.
Set the unit to cooling operation, and check the
temperature of the liquid pipe to see if the
electronic expansion valve works.
—
Diagnose with remote controller
indication.
—
94
Diagnose by service port pressure
and operating current.
Check for refrigerant shortage. 104
operating noise and
vibrations
Check the output voltage of the
power module.
—
153
Check the power module. — —
Check the installation condition. Check if the required spaces for installation
(specified in the installation manual) are
provided.
—