Haier 1U25MECFRA-3 Service Manual page 33

10.2 Problem Symptoms and Measures
S y m p o t m
Check the power supply.
None of the units
operates
Operation
Check the power supply.
sometimes stops.
Check for faulty operation
Equipment
operates but
does not cool, or
does not heat
(only for heat
pump)
Diagnosis by service port
Large operating
noise and
vibrations
C h e c k I e t m
Check the indoor PCB
of the electronic
expansion valve.
pressure and operating
current.
Check the installation
condition.
D t e
Check to make sure that the rated voltage is supplied.
Check to make sure that the indoor PCB is broken
A power failure of 2 to 10 cycles can stop air conditioner
operation.
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.
Check for insufficient gas.
Check to make sure that the required spaces for
installation (specified in the Technical Guide, etc.) are
provided.
31
Service diagnosis
i a s l f o M e a s u e r
Domestic air conditioner