Haier 1U18BR4EAA, Service Manual

Page: 16 / 35

Service diagnosis
Domestic air conditioner
8.3 Problem Symptoms and Measures
Symptom Check Item Details of Measure
None of the units
operates
Check the power supply. Check to make sure that the rated voltage is supplied.
Check the indoor PCB Check to make sure that the indoor PCB is broken
Operation
sometimes stops.
Check the power supply.
A power failure of 2 to 10 cycles can stop air conditioner
operation.
Equipment
operates but
does not cool, or
does not heat
(only for heat
pump)
Check for faulty operation
of the electronic
expansion valve.
Set the units to cooling operation, and compare the
temperatures of the liquid side connection pipes of the
connection section among rooms to check the opening and
closing operation of the electronic expansion valves of the
individual units.
Diagnosis by service port
pressure and operating
current.
Check for insufficient gas.
Large operating
noise and
vibrations
Check the installation
condition.
Check to make sure that the required spaces for
installation (specified in the Technical Guide, etc.) are
provided.
14