The Following Symptoms Are Normal - Mitsubishi Electric CITY MULTI PUHY-P108 Service Handbook

[6] The following symptoms are normal.

Symptoms
The indoor unit does not start
after starting cooling (heating)
operation.
The auto vane adjusts its posi-
tion by itself.
The fan stops during heating
operation.
The fan keeps running after
the unit has stopped.
The fan speed does not reach
the set speed when operation
switch is turned on.
When the main power is
turned on, the display shown
on the right appears on the in-
door unit remote controller for
5 minutes.
Indoor unit and BC controller
make noise during cooling/
heating changeover.
Sound of the refrigerant flow is
heard from the indoor unit im-
mediately after starting opera-
tion.
Remote controller dis-
play
"Cooling (heat- The unit cannot perform a heating (cooling) operation when other in-
ing)" icon blinks door units are performing a cooling (heating) operation.
on the display.
Normal display After an hour of cooling operation with the auto vane in the vertical
position, the vane may automatically move into the horizontal posi-
tion.
Louver blades will automatically move into the horizontal position
while the unit is in the defrost mode, pre-heating stand-by mode, or
when the thermostat triggers unit off.
Defrost The fan remains stopped during defrost operation.
Display is off. When the auxiliary heater is turned on, the fan operates for one
minute after stopping to dissipate heat.
STAND BY The fan operates at extra low speed for 5 minutes after it is turned on
or until the pipe temperature reaches 35°C[95°F], then it operates at
low speed for 2 minutes, and finally it operates at the set speed.
(Pre-heating stand-by)
"HO" or "PLEASE The system is starting up. Wait until the blinking display of "HO" or
WAIT" icons "PLEASE WAIT" go off.
blink on the dis-
play.
Normal display This noise is made when the refrigerant circuit is reversed and is nor-
mal.
Normal display This is caused by the transient instability of the refrigerant flow and
is normal.
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[ VIII Test Run Mode ]
Cause