Troubleshooting - Mitsubishi Electric City Multi PEFY-P-NMHU-E Manuel D'utilisation

6. Troubleshooting

Before you ask for repair service, check the following points:
State of Machine Remote Controller
" " display is not lit up.
No display appears
It does not run.
even when the [ON/
O F F ] b u t t o n i s
pressed.
A i r f l o w s o u t b u t i t The liquid crystal dis-
does not cool enough play shows that it is in
or heat enough. the state of operation.
The liquid crystal dis-
Cool air or warm air
play shows that it is in
does not come out.
operation.
T h e " C H E C K " a n d
It runs briefly, but soon check code flashes on
stops. the liquid crystal dis-
play.
The sound of the ex-
haust and rotation of All lights are out ex-
the motor can still be cept the powered dis-
heard after stop of run- play of " ".
ning.
The sound of the ex-
haust and the rotation All lights are out ex-
of the motor can be cept the powered dis-
heard intermittently play of " ".
after stop of running.
Warm air comes out
The liquid crystal dis-
intermittently when the
play shows that it is in
thermostat is OFF or
the state of operation.
during fan operation.
• If operation stops due to a power failure, the [restart-preventing circuit at power failure] operates and disables unit operation even after power restoration. In this case,
press the [ON/OFF] button again and start operation.
If malfunctions persist after you have checked the above, turn the power supply OFF and contact your dealer with information about the product name, the nature of the
malfunction, etc. If the display of "[CHECK]" and (4 digit) check code flashes, tell the dealer contents of the display (check code). Never attempt to repair by yourself.
The following symptoms are not air conditioner failures:
• The air blown out from the air conditioner can sometimes give off odors. This is due to cigarette smoke contained in the air of the room, the smell of cosmetics, the
walls, furniture, etc., absorbed in the air conditioner.
• A hissing noise can be heard immediately after the air conditioner is started or stopped. This is the sound of the refrigeration flowing inside the air conditioner. This is
normal.
• The air conditioner sometimes snaps or clicks at the beginning or end of cooling/heating operation. This is the sound of friction on the front panel and other sections
due to expansion and contraction caused by temperature change. This is normal.
• The fan speed changes in spite of not changing the setting. Not to blow out cold air at the beginning of heating operation, the air conditioner automatically adjusts the
fan speed gradually from lower to the set speed. It also adjust its fan speed to protect the fan motor when return air temperature or fan speed excessively rises.
8
Cause
Power failure
The power supply is turned OFF.
The fuse in the power supply is gone.
The earth leakage breaker is gone.
Improper temperature adjustment
The filter is filled with dust and dirt.
There are som obstacles at the air inlet and outlet of
the indoor and outdoor units.
Windows and doors are open.
The restart-preventing circuit is in operation for 3
minutes.
Indoor unit operation was restarted during the heat-
ing and defrosting operation.
There are some obstacles at the air inlet and outlet
of the indoor and outdoor units.
The filter is filled with dust and dirt.
When other indoor units are engaged in cooling op-
eration, the machine stops after running a drain-up
mechanism for 3 minutes when air-cooling operation
is stopped.
When other indoor units are engaged in cooling
operation, drained water is brought in. If the drain
water is collected, the drain-up mechanism initiates a
draining operation.
When other indoor units are engaged in heating
operation, the control valves are opened and closed
from time to time to maintain the stability of the sys-
tem.
Troubleshooting
Press the [ON/OFF] button after power restoration.
Turn the power supply ON.
Replace fuse.
Put in the earth leakage breaker.
After checking the set temperature and inlet temperature
on the liquid crystal display, refer to [Room temperature
adjustment], and operate the adjustment button.
Clean up the filter.
(Refer to [Caring for the machine].)
Remove.
Close
Wait for a while.
(To protect the compressor, a 3-minute restart-preventing
circuit is built into the indoor unit. Therefore, there are oc-
casions sometimes when the compressor does not start
running immediately. There are cases when it does not run
for as long as 3 minutes.)
Wait for a while.
(Heating operation starts after ending defrosting opera-
tion.)
Rerun after removal
Rerun after cleaning the filter. (Refer to [Caring for the ma-
chine].)
Wait for 3 minutes.
It soon stops. (If the noise occurs more than 2-3 times in
an hour, ask for repair service.)
It soon stops. (If the room temperature rises uncomfortably
high in a small room, stop operation.)