GVZC20 Service Manual
SERVICING
41
TROUBLESHOOTING-INDOOR UNIT FOR EEV APPLICABLE UNIT
On Normal Operation
Eb NO HTR KIT INSTALLED - SYSTEM CALLING FOR AUXILIARY HEAT (Minor Error Code)
Ed HEATER KIT DIP SWITCHES NOT SET PROPERLY
E5 FUSE OPEN
EF AUXILIARY SWITCH OPEN
d0 DATA NOT ON NETWORK
d1 INVALID DATA ON NETWORK
d4 INVALID Bluetooth
TM
SHARED DATA LOADER DATA
b0 BLOWER MOTOR NOT RUNNING
b1 BLOWER MOTOR COMMUNICATION ERROR
b2 BLOWER MOTOR HP (Horse power) MISMATCH
b3 BLOWER MOTOR OPERATING IN POWER, TEMP., OR SPEED LIMIT
b4 BLOWER MOTOR CURRENT TRIP OR LOST ROTOR
b6 OVER/UNDER VOLTAGE TRIP OR OVER TEMPERATURE TRIP
b7 INCOMPLETE PARAMETER SENT TO MOTOR
b9 LOW INDOOR AIRFLOW (Minor Error Code) (without EH mode)
9b
LOW INDOOR AIRFLOW
(Major Error Code) (EH mode only)
70 EEV DISCONNECTION DETECTED
73 LIQUID SIDE THERMISTOR ABNORMALITY
74 GAS SIDE THERMISTOR ABNORMALITY
75 PRESSURE SENSOR ABNORMALITY
77
INDOOR UNIT - THERMOSTAT COMMUNICATION ERROR
(STARTUP OPERATION & DURING OPERATION)
Hu
HUMIDIFICATION DEMAND
(Running without heating)
FC FAN COOL - COMMUNICATING MODE ONLY (Fan Demand-Cool)
FH FAN HEAT - COMMUNICATING MODE ONLY (Fan Demand-Heat)
F FAN ONLY (Fan Demand-Manual)
H1 ELECTRIC HEAT LOW (Heat Demand, Back-up Heat Demand)
H2 ELECTRIC HEAT HIGH (Heat Demand, Back-up Heat Demand)
dF DEFROST - COMMUNICATING MODE ONLY (note: defrost is displayed as H1 in a legacy setup)
7 SEGMENT LED
DISPLAY
DESCRIPTION OF CONDITION
DIAGNOSTIC CODES