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Service Manual -
HRG18xxS1P
508206-01
Issue 2140
Page 33 of 83
GF= Gas Furnace, AH=Air Handler, ID=Indoor unit (GF or AH), HP=Heat Pump, AC=Air Conditioner, OD=Outdoor Unit (AC or HP), ZA=Zone system and TS=Thermostat
Alert
Code
Inverter
Code
Inverter Flash
Code
Priority
Condition
Actual Displayed
Alert Text
Component or System Operational State
and Troubleshooting Tip
How to Clear
Alert Code
Red
LED
Green
LED
427
21
2
flashes
1 flash
Service
Soon/
Service
Urgent
OD Inverter DC
Peak Fault
The inverter has detected a DC peak fault condition.
• If condition (55A or higher) is detected, outdoor unit will stop (compressor
and fan) – moderate condition.
• Anti-short cycle is initiated.
• If peak current (55A or higher) occurs 10 times within an hour, system will
lockout – critical condition.
• Inverter LEDs will flash code 21.
• If the unit is a variable capacity heat pump, this error may occur entering
or exiting a defrost cycle as the compressor restarts after the 30 second
compressor shift delay. If the unit was manufactured prior to serial
number 5817F and has frequent alert code 427, then compare the
inverter part number to the latest part number listed in the unit repair
parts. Units produced after serial number 5817F which is listed on the
unit name plate have an inverter with updated software that includes
compressor current slope logic to reduce the potential of alert code 427
instances from occurring during defrost. Replace the inverter with the
latest inverter if necessary.
• Refer to the unit service documentation for detailed troubleshooting
procedures.
NOTE:
Serial number format on unit name plate is PPYYMNNNNN (PP
= Manufacturing Plant, YY and M represents the year and month
made.
Inverter flash code 21.
The sequence is:
• Red LED: Two Flashes
• Green LED: One Flash
NOTE:
Inverter normal operations with no error code present is as
follows. Red LED is ON and Green LED is OFF.
To clear, disconnect
and reconnect power
to outdoor control.
428
22
2
flashes
2
flashes
Service
Soon/
Service
Urgent
OD Inverter
High Main Input
Current
The inverter has detected a high main input current condition.
• If condition is detected, outdoor unit will stop (compressor and fan) –
moderate condition.
• Anti-short cycle is initiated.
• If condition occurs 10 times within an hour, system will lockout – critical
condition.
• Inverter LEDs will flash code 22.
• Refer to the unit service documentation for detailed troubleshooting
procedures.
Inverter flash code 22.
The sequence is:
• Red LED: Two Flashes
• Green LED: Two Flashes
NOTE:
Inverter normal operations with no error code present is as
follows. Red LED is ON and Green LED is OFF.
To clear, disconnect
power to outdoor unit
and restart.
Table 12. Alert Codes and Troubleshooting