Mitsubishi Electric Mr.Slim PUZ-HA42NKA Service Manual page 45

Phone Calls From Customers
The room cannot be cooled or heated sufficiently.
1 An gas escaping sound is heard
Sound
comes out
sometimes.
from the air
conditioner.
2 A cracking sound is heard
sometimes.
3 A buzzing sound is heard
sometimes.
4 A ticking sound is heard from
the outdoor unit sometimes.
5 A sound, similar to water
flowing, is heard from the unit.
1 The fan speed doesn't match
Something
is wrong
the setting of the remote
with the
controller during DRY
blower.....
operation.(No air comes out
sometimes during DRY
operation.)
2 The fan speed doesn't match
the setting of the remote
controller in HEAT operation.
OCH567
How to Respond
1 Check the set temperature of remote controller.
The outdoor unit cannot be operated if the set
temperature is not appropriate.
The outdoor unit operates in the following modes.
COOL: When the set temperature is lower
than the room temperature.
HEAT: When the set temperature is higher
than the room temperature.
2 Check if filters are not dirty and clogged. If filters
are clogged, the airflow amount will be reduced
and the unit capacity will be lowered. See the
instruction manual that came with the product for
how to clean the filters.
3 Check there is enough space around the air
conditioner.
If there are any obstacles in the air intake or air outlet
of indoor/outdoor units, they block the airflow
direction so that the unit capacity will be lowered.
1 This is not a malfunction.
This is the sound which is heard when the flow of
refrigerant in the air conditioner is switched.
2 This is not a malfunction.
This is the sound which is heard when internal
parts of units expand or contract when the
temperature changes.
3 This is not a malfunction.
This is the sound which is heard when the outdoor
unit starts operating.
4 This is not a malfunction.
This is the sound which is heard when the blower
of the outdoor unit is controlling the airflow amount
in order to keep the optimum operating condition.
5 This is not a malfunction.
This is the sound which is heard when the
refrigerant is flowing inside the indoor unit.
1 This is not a malfunction. During the DRY
operation, the blower's ON/OFF is controlled by
the microcomputer to prevent overcooling and to
ensure efficient dehumidification. The fan speed
cannot be set by the remote controller during DRY
operation.
2 This is not a malfunction.
1) When the HEAT operation starts, to prevent the
unit from blowing cold air, the fan speed is
gradually increased from zero to the set speed,
in proportion to the temperature rise of the
discharged air.
2) When the room temperature reaches the set
temperature and the outdoor unit stops,
the unit starts the LOW AIR operation.
3) During the HEAT operation, the DEFROST
operation is performed to defrost the outdoor
unit. During the DEFROST operation, the
blower is stopped to prevent cold air coming
out of the indoor unit.
Note
The up/down vane will be
automatically set to
horizontal blow in these
cases listed up on the left
(1–3). After a while, the
up/down vane will be
automatically moved
according to the setting of
the remote controller.