GVZC20 Service Manual

TROUBLESHOOTING
97
Fault Code
Control Board
LED Display
Transmitted Climate
Talk Message
Thermostat Fault Probable Causes Corrective Actions
12 E12 OD CTRL FAIL1
Indicates a general memory error.
● High electrical noise
● Faulty control board
● Replace control board if necessary
13 E13
HI PRESSURE C (C =
CRITICAL)
This error indicates the equipment
is experiencing frequent high
pressure faults.
● Blocked/restricted condenser coil
and/or lines
● Stop valve not completely open
● Overcharge
● Outdoor fan not running
● High pressure switch (HPS)
inoperable
● Faulty TXV
● Faulty control board
● Check and clean condenser coil and/or lines
● Check the opening of stop valve, should be
full open; Repair/replace if needed
● Check refrigerant charge level; Adjust if
needed
● Check outdoor fan motor & wiring;
Repair/replace if needed
● Check TXV; Replace if needed
● Replace control board if necessary
14 -
HI PRESSURE M (M =
MINOR)
This error indicates the equipment
is experiencing frequent high
pressure faults. Control has
determined continued operation is
acceptable. This indicates they
may be a problem with the
equipment.
● Blocked/restricted condenser coil
and/or lines
● Stop valve not completely open
● Overcharge
● Outdoor fan not running
● High pressure switch (HPS)
inoperable
● Faulty TXV
● Faulty control board
● Check and clean condenser coil and/or lines
● Check the opening of stop valve, should be
full open; Repair/replace if needed
● Check refrigerant charge level; Adjust if
needed
● Check outdoor fan motor & wiring;
Repair/replace if needed
● Check TXV; Replace if needed
● Replace control board if necessary
● Check high pressure switch; Replace if
necessary
15 E15 LOW PRESSURE C
This error indicates the equipment
is experiencing frequent low
pressure faults.
● Stop valve not completely open
● Restriction in refrigerant lines
● Low refrigerant charge
● Refrigerant leak
● Low pressure sensor inoperable or
not properly connected
● Indoor fan motor not functioning
correctly
● Faulty TXV
● Faulty control board
● Check the opening of stop valve, should be
full open; Repair/replace if needed
● Check for restrictions in refrigerant line;
Repair/replace if needed
● Check refrigerant charge level; Adjust if
needed
● Test for system leaks using leak test
procedure
● Check the connection to low pressure sensor;
Repair/replace if needed
● Check TXV; Replace if needed
● Check indoor blower motor & wiring;
Repair/replace if needed
● Replace control board if necessary
16 - LOW PRESSURE M
This error indicates the equipment
is experiencing frequent low
pressure faults. Control has
determined continued operation is
acceptable. This indicates they
may be a problem with the
equipment.
● Stop valve not completely open
● Restriction in refrigerant lines
● Low refrigerant charge
● Refrigerant leak
● Low pressure sensor inoperable or
not properly connected
● Indoor fan motor not functioning
correctly
● Faulty TXV
● Faulty control board
● Check the opening of stop valve, should be
full open; Repair/replace if needed
● Check for restrictions in refrigerant line;
Repair/replace if needed
● Check refrigerant charge level; Adjust if
needed
● Test for system leaks using leak test
procedure
● Check the connection to low pressure sensor;
Repair/replace if needed
● Check TXV; Replace if needed
● Check indoor blower motor & wiring;
Repair/replace if needed
● Replace control board if necessary
17 E17 COMPRESSOR FAIL
This error indicates the equipment
is experiencing frequent
compressor faults.
● Stop valve not completely open
● The compressor wire is lost phase
● Compressor motor failure
● Check the opening of stop valve, should be
full open; Repair/replace if needed
● Check the wire between control board and
compressor
● Inspect compressor motor for proper function;
Replace if necessary
18 E18 OD CTRL FAIL2
Indicates the control board may
need to be replaced.
● Outdoor fan motor not connected
properly
● Faulty control board
● Noise
● Check wiring from Outdoor fan motor to
control board; Repair if needed.
● Replace control board if necessary
19 E19 PCB OR FAN FAIL
This error indicates the equipment
is experiencing frequent outdoor
control board and/or motor faults.
● Obstruction in fan rotation
● Outdoor fan motor not connected
properly
● Outdoor fan not running
● Faulty control borad
● Noise
● Check and clean grille or any debris
● Check wiring from Outdoor fan motor to
control board; Repair if needed
● Check outdoor fan motor & wiring.
Repair/replace if needed
● Replace control board if necessary
20 E20 EEV OPEN CKT
EEV coil is not connected.
● Outdoor EEV coil is not connected.
● Faulty outdoor EEV coil.
● Check outdoor EEV coil connection.
Repair/replace as needed.
21 E21 EEV CTRL FAIL
This error indicates the equipment
is experiencing frequent low
discharge superheat faults.
● Thermistors inoperable or improperly
connected
● Faulty TXV
● Faulty outdoor EEV coil
● Faulty outdoor EEV
● Over charge
● Faulty pressure sensor
● Faulty control board
● Check the connection to thermistors;
Repair/replace if needed
● Check TXV; Replace/repair if needed
● Check outdoor EEV coil; Repair/replace if
needed
● Check outdoor EEV; Replace/repair if needed
● Check refrigerant charge level; Adjust if
needed
● Check pressure sensor; Repair/replace if
needed
● Replace control board if necessary
(*1) This message displayed when using the CTKO4 thermostat.
(*2) This specication of *VZC20**1 or earlier model are di󰀨erent from this specication. For details, see the service manual that matches the major revisoin of model name.