17
Table 6 — Troubleshooting
Replacement Parts —
Quote the unit model number
and unit serial number when ordering replacement parts or
contacting the factory about the unit. This information can be
found on the serial plate attached to the unit. See Fig. 29.
DIGITAL DISPLAY
DESCRIPTION
POSSIBLE CAUSES
POSSIBLE SOLUTIONS
dd
Heating/Cooling Mode Conflict
System is in cooling or fan mode only and
heating signal is received from a unit in
the system.
All units should be in cooling mode for system to stay
in cooling mode.
System is in heating mode and cooling
signal is received from a unit in the
system.
All units should be in heating mode.
E1
Communication Error Between Indoor
and Outdoor Unit
Signal wires are short-circuited or
disconnected.
Check or reconnect signal wire.
Signal wires close to electromagnetic
source.
Distance signal wires from electromagnetic source.
PC board fault.
Replace PC board.
E2, E4, E5
Check Temperature Sensor
Loose connection at port on PC board.
Tighten the connection at port on PC board.
Sensor is short-circuited.
Using multi-meter, measure resistance of the sensor.
If the resistance is ≤ 100 ohms, change the sensor.
PC board fault.
Replace PC board.
E6
Check DC Fan Motor
Operating beyond limits.
Check and correct external static pressure on the
unit.
DC motor fault.
Replace DC motor.
PC board fault.
Replace PC board.
E7
EEPROM Error (Data Storage)
Chip or PC board fault.
Replace PC board.
E9
Communication Error Between Indoor
Unit and Controller
Signal wires are short-circuited or
disconnected.
Check or reconnect signal wires.
Signal wires close to electromagnetic
source.
Distance signal wires from electromagnetic source.
PC board fault.
Replace PC board.
Eb
EEV Error
EEV wires are short-circuited or
disconnected.
Check or reconnect signal wire.
EEV stop.
Replace EEV.
PC board fault.
Replace PC board.
Ed
Outdoor Unit Error
Outdoor unit fault.
Refer to outdoor unit troubleshooting guide.
EE
Condensate Overflow
Loose connection or disconnected at port
on PC board.
Tighten the connection or reconnect at port on PC
board.
Condensate switch float is stuck.
Inspect the float.
Trap slope is too steep.
Adjust the trap slope.
Drain pipe is too long.
Adjust the length of the drain pipe.
Drain pump faulty.
Replace the drain pump.
FE
No Address When Powered ON For
First Time
Indoor unit without address.
Run automatic addressing option at the outdoor unit.
Use remote wireless or wired controller to readdress
the indoor unit.
UU
MDC In Auto System-Check Mode
MDC Fault.
Refer to MDC troubleshooting guide.
LEGEND
EEPROM
—
Electronically Erasable Programmable Read-only Memory
EEV
—
Electronic Expansion Valve
MDC
—
Multiport Distribution Controller
PC
—
Process Controller
Fig. 29 — Unit Serial Plate (Example)
