Service Manual

SiUS041638E General Problem Symptoms and Check Items
Service Diagnosis 52
1. General Problem Symptoms and Check Items
Symptom Check Item Details 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/cooling operations are not available when
the outdoor temperature is out of the operation
limit. Check the reference page for the operation
limit.
117
Diagnose with remote controller
indication.
—57
Check the remote controller
addresses.
Check if address settings for the remote controller
and indoor unit are correct.
108
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/cooling operations are not available when
the outdoor temperature is out of the operation
limit. Check the reference page for the operation
limit.
117
Diagnose with remote controller
indication.
—57
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.
—57
Diagnose by service port pressure
and operating current.
Check for refrigerant shortage.
—
Large operating noise and
vibrations
Check the output voltage of the
power module.
—101
Check the power module. — —
Check the installation condition. Check if the required spaces for installation
(specified in the installation manual) are provided.
—