INVENTOR U4MRS-18, User Manual, Page: 13 / 44

ƒ
Page 12
„
Problem Possible Causes
Dust is emitted from
either the indoor or
outdoor unit
The unit may accumulate dust during extended periods of non-use, which
will be emitted when the unit is turned on. This can be mitigated by covering
the unit during long periods of inactivity.
The unit emits a
bad odor
The unit may absorb odors from the environment (such as furniture, cooking,
cigarettes, etc.) which will be emitted during operations.
The unit’s filters have become moldy and should be cleaned.
The fan of the
outdoor unit
does not operate
During operation, the fan speed is controlled to optimize product operation.
Troubleshooting Tips
When troubles occur, please check the following points before contacting a repair company.
Problem Possible Causes Solution
The unit
is not
working
Power failure Wait for the power to be restored
The power switch is off Turn on the power
The fuse is burned out Replace the fuse
Remote control batteries are dead Replace the remote control batteries
The unit’s 3-minute protection has
been activated
Wait three minutes after restarting the unit
Poor cooling
performance
Temperature setting may be higher
than the ambient room temperature Lower the temperature setting
The heat exchanger on the indoor
or outdoor unit is dirty
Clean the affected heat exchanger
The air filter is dirty
Remove the filter and clean it according
to instructions
The air inlet or outlet of either unit
is blocked
Turn the unit off, remove the obstruction
and turn it back on
Doors and windows are open
Make sure that all doors and windows are
closed while operating the unit
Excessive heat is generated by
sunlight
Close windows and curtains during
periods of high heat or bright sunshine
Low refrigerant due to leak or
long-term use
Check for leaks, re-seal if necessary and
top off refrigerant
The unit
starts and
stops
frequently
There’s too much or too little
refrigerant in the system
Check for leaks and recharge the system
with refrigerant
There is air, incompressible gas or
foreign material in the refrigeration
system.
Evacuate and recharge the system with
refrigerant
System circuit is blocked
Determine which circuit is blocked and replace
the malfunctioning piece of equipment
The compressor is broken Replace the compressor
The voltage is too high or too low Install a manostat to regulate the voltage
Poor heating
performance
The outdoor temperature is lower
than 7°C (44.5°F)
Check for leaks and recharge the system
with refrigerant
Cold air is entering through doors
and windows
Make sure that all doors and windows are
closed during use
Low refrigerant due to leak or
long-term use
Check for leaks, re-seal if necessary and
top off refrigerant
ƒ
Page 13
„
Error Codes
1
Indoor EEPROM (Electrically Erasable
Programmable Read-Only Memory) error
1 Off
E0
2 Indoor and outdoor unit communication malfunction 2 Off
E 1
3 Indoor fan speed malfunction 4 Off
E3
4 Indoor room temperature sensor error 5 Off
E4
5 Evaporator coil temperature sensor error 6 Off
E5
6 Refrigerant leak detection system malfunction 7 Off
EC
7 Water level alarm malfunction 8 Off
EE
8
Dual indoor unit (twin model only)
communication malfunction
9 Off
E8
9 Other twin model malfunction 10 Off
E9
10 Overload protection 1 On
F0
11 Outdoor temperature sensor error 2 On
F 1
12 Outdoor condenser pipe sensor error 3 On
F2
13 Discharge air temperature sensor error 4 On
F3
14
Outdoor EEPROM (Electrically Erasable
Programmable Read-Only Memory) error
5 On
F4
15 Outdoor fan speed (DC fan motor only) malfunction 6 On
F5
16 T2b sensor error 7 On
F6
17 Auto-lifting panel communication error 8 On
F7
18 Auto-lifting panel malfunction 9 On
F8
19 Auto-lifting panel is open 10 On
F9
20 Inverter module IPM protection 1 Flash
P0
21 High/Low voltage protection 2 Flash
P 1
22 Compressor top overheating protection 3 Flash
P2
23 Outdoor low temperature protection 4 Flash
P3
24 Compressor drive error 5 Flash
P4
25 Mode conflict 6 Flash
P5
26 Compressor low-pressure protection 7 Flash
P6
27 Outdoor IGBT sensor error 8 Flash
P7