Service Call Q & A - Hitachi RAK-25NH4 Service Manual

SERVICE CALL Q & A
Model RAK-25NH4 / RAC-25NH4
RAK-35NH4 / RAC-35NH4
RAK-50NH4 / RAC-50NH4
COOLING MODE
The compressor has
Q1
stopped suddenly during
cooling operation.
DEHUMIDIFYING MODE
Q2
Sound of running water is heard from
indoor unit during dehumidifying.
Q3
Compressor occasionally does not
operate during dehumidifying.
HEATING MODE
Q4
The circulation stops
occasionally during
Heating mode.
Q5
When the fan speed is set
at HIGH or MED, the flow
is actually Weak.
Q6
Heating operation stops
while the temperature is
preset at "30".
A1
Check if the indoor heat
exchanger is frosted.
Wait for 3-4 minutes
until it is defrosted.
A2
Normal sound when refrigerant flows in pipe.
Compressor may not operate when room
A3
temperature is 10°C or less. It also stops
when the humidity is preset humidity or less.
A4
It occurs during defrost-
ing. Wait for 5-10
minutes until the
condenser is defrosted.
A5
At the beginning of heating,
the fan speed remains
LOW for 30 seconds. If
HIGH is selected, it
switches to LOW and again
to MED after additional 30
seconds.
A6
If temperature is high in
the outdoor, heating
operation may stop to
protect internal devices.
– 93 –
If the air conditioner operates
in cooling mode when it is
cold, the evaporator may get
frosted.