Carrier 40VMH024 - Page 30

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Table 6 —Troubleshooting
LEGEND
EEV - Electronic Expansion Valve
EEPROM - Electronically Erasable Programmable Read-only Memory
MDC - Multiport Distribution Controller
PC - Process Controller
ERROR DESCRIPTION POSSIBLE CAUSES POSSIBLE SOLUTIONS
dd
Heating / Cooling Mode Conflict
System is in cooling or fan only mode, and
heating signal is received from a unit on 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
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 wire 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 DC Fan Motor
Operating beyond limits
Check and correct external static pres-
sure 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
Replace EEV wires
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 Error
Loose connection or disconnected
Tighten the connection or reconnect at
port on PC board
Water level float is stuck Inspect the slope
Trap slope is too steep Adjust the trap slope
Drain pipe is too long Adjust the length of drain pipe
Drain pump faulty Replace the drain pump
FE
No Address When Power ON for
first time
Indoor unit without address
Run automatic addressing option at the
outdoor unit
Use remote wireless or wired controller to
re-address indoor unit
UU MDC Auto System-Check Mode MDC fault Refer to MDC troubleshooting guide