Hitachi RAS-18LH2 Service Manual page 50

Heating operation
Air does not come out
Q6
when starting a heating
operation.
Air does not come out
Q7
sometimes while in a heating
operation.
The fan speed is set to "HI"
Q8
or "MED" but the heating
operation starts with a LO
fan speed.
The operation stops during
Q9
a heating operation while
the room temperature is set
at "30".
The outdoor fan does not
Q10
move at a heating operation
by the service switch.
Auto fresh defrosting
Heating has been turned off by the main
Q11
operation but the "Hot keep lamp" lights and
the outdoor unit operations.
It is not a trouble. The fan is
A6
stopped to avoid cold wind.
Defrosting is on. Wait for
A7
5 – 1 0 m i n u t e s u n i t t h e
outdoor unit is defrosted.
The heating operation starts
A8
with a LO fan speed for 30
seconds. If the fan speed
is set to HI, the operation
starts with LO fan speed,
followed by MED fan speed
for 30 seconds and then by
HI fan speed.
If a heating operation is
A9
performed when the exterior
temperature is high, the
operation may stop to protect
the equipment.
It is not a trouble.
A10
When heating, the outdoor
fan is stopped to avoid
excessive pressure rise.
A11
– 55 –
When starting the operation,
the heat exchanger is cold
and, therefore, the fan is
stopped.
Wait 2–3 minutes.
"Auto fresh defrosting" operates. When
stopping the operation, whether the outdoor
unit is frosted or not is checked and, if in
the affi rmative, defrosting is performed before
stopping the operation.