Mitsubishi Electric CITY MULTI PKFY-P-VKM-E Série Manuel D'utilisation page 18

Having trouble?
Noise is louder than specifications.
Nothing appears in the wireless remote controller display, the display
is faint, or signals are not received by the indoor unit unless the remote
controller is close.
The operation lamp near the receiver for the wireless remote controller
on the indoor unit is flashing.
Warm air blows from the indoor unit intermittently when heat mode is off
or during fan mode.
The range of working temperatures for both the indoor and outdoor units of the series Y, R2, Multi-S is as below.
Here is the solution. (Unit is operating normally.)
The indoor operation sound level is affected by the acoustics of the
particular room as shown in the following table and will be higher than
the noise specification, which was measured in an echo-free room.
High sound-
absorbing rooms
Location Broadcasting
examples studio, music
room, etc.
Noise levels 3 to 7 dB
The batteries are low.
Replace the batteries and press the Reset button.
If nothing appears even after the batteries are replaced, make sure
that the batteries are installed in the correct directions (+, –).
The self diagnosis function has operated to protect the air conditioner.
Do not attempt to repair this equipment by yourself.
Turn off the power switch immediately and consult your dealer. Be
sure to provide the dealer with the model name.
When another indoor unit is operating in heat mode, the control
valve opens and closes occasionally to maintain stability in the air
conditioning system. This operation will stop after a while.
* If this will cause an undesirable rise in the room temperature in
small rooms, etc., stop the operation of the indoor unit temporarily.
Normal rooms Low sound-
absorbing rooms
Reception room, Office, hotel
hotel lobby, etc. room
6 to 10 dB 9 to 13 dB