Rheem AC Error
Codes
Display Codes 0– standby
Diagnostic
Description No command for unit operation
Possible Cause normal operation
Possible Cause normal operation
Display Codes c – first stage
Diagnostic Description The cooling unit has received a command for first stage cooling
Possible Cause normal operation
Diagnostic Description The cooling unit has received a command for first stage cooling
Possible Cause normal operation
Display Codes c flashing
Diagnostic Description Anti-short cycle timer (3 min.) or minimum run timer (30 sec) active
Diagnostic Description Anti-short cycle timer (3 min.) or minimum run timer (30 sec) active
Possible Cause
• The unit has received a command for first stage cooling during an active anti-short cycle timer or a minimum run timer.
• Wait until the unit timer expires or press the test button to defeat the short cycle delay.
• The unit has received a command for first stage cooling during an active anti-short cycle timer or a minimum run timer.
• Wait until the unit timer expires or press the test button to defeat the short cycle delay.
Display
Codes C – Second stage coolant
Diagnostic Description The unit has got command for second stage cooling
Possible Cause normal operation
Diagnostic Description The unit has got command for second stage cooling
Possible Cause normal operation
Display Codes C flashing
Diagnostic Description Anti-short cycle timer (3 min.) or minimum run timer (30 sec) active
Diagnostic Description Anti-short cycle timer (3 min.) or minimum run timer (30 sec) active
Possible Cause
• During an active anti-short cycle timer or minimum run timer, the unit has received a command for second stage cooling.
• Wait unit timer has expired or press test button to defeat short cycle delay.
• During an active anti-short cycle timer or minimum run timer, the unit has received a command for second stage cooling.
• Wait unit timer has expired or press test button to defeat short cycle delay.
Display Codes H – First stage heat
pump
Diagnostic Description The unit has received a command for the first stage heat pump
Possible Cause normal operation
Diagnostic Description The unit has received a command for the first stage heat pump
Possible Cause normal operation
Display Codes H flash
Diagnostic Description Anti-short cycle timer (3 min.) or minimum run timer (30 sec) action
Diagnostic Description Anti-short cycle timer (3 min.) or minimum run timer (30 sec) action
Possible Cause
• The unit has received a command for active anti-short cycle timer or first stage heat pump during minimum run time
• Wait unit timer has expired or press test button to defeat short cycle delay
• The unit has received a command for active anti-short cycle timer or first stage heat pump during minimum run time
• Wait unit timer has expired or press test button to defeat short cycle delay
Display Codes H – Second Stage Heat
Pum
Diagnostic Description The unit has received command for second stage heat pump
Possible Cause normal operation
Diagnostic Description The unit has received command for second stage heat pump
Possible Cause normal operation
Display Codes H flashing
Diagnostic Description Anti-short cycle timer (3 min.) or minimum run timer (30 sec) active
Diagnostic Description Anti-short cycle timer (3 min.) or minimum run timer (30 sec) active
Possible Cause
• During an active anti-short cycle timer or minimum run timer, the unit has received a command for a second stage heat pump.
• Wait unit timer has expired or press test button to defeat short cycle delay
• During an active anti-short cycle timer or minimum run timer, the unit has received a command for a second stage heat pump.
• Wait unit timer has expired or press test button to defeat short cycle delay
Display Codes D – Defrost Active
Diagnostic Description The A/C is going through a defrost cycle
Possible Cause normal operation
Diagnostic Description The A/C is going through a defrost cycle
Possible Cause normal operation
Display Codes t – test mod
Diagnostic Description Test mod
Possible Cause ICC is in test mode
Diagnostic Description Test mod
Possible Cause ICC is in test mode
Display Codes P-Guard Trip
Diagnostic Description A command exists for compressor operation but no current is measured for the compressor
Diagnostic Description A command exists for compressor operation but no current is measured for the compressor
Possible Cause
Motor protector open
Motor protector open
Display
Codes 01 – Long Run Time (Compressor)
Diagnostic Description In mode cooling the compressor has run continuously for more than 18 hours.
Diagnostic Description In mode cooling the compressor has run continuously for more than 18 hours.
Possible Cause
• low refrigerant charge
• There is enough leakage in the air ducts
• dirty indoor air filter
• dirty outdoor coil
• low refrigerant charge
• There is enough leakage in the air ducts
• dirty indoor air filter
• dirty outdoor coil
Display
Codes 02 – High Pressure
Diagnostic Description The compressor limit is opened four (4) times within a call to operation.
Diagnostic Description The compressor limit is opened four (4) times within a call to operation.
Possible Cause
• External coils are dirty ( mode cooling)
• Outdoor fan is not running (mode cooling )
• Dirty indoor coil or filter (mode heating )
• Indoor blower is not running (mode heating )
• liquid line restrictions
• excessive refrigerant charge
• External coils are dirty ( mode cooling)
• Outdoor fan is not running (mode cooling )
• Dirty indoor coil or filter (mode heating )
• Indoor blower is not running (mode heating )
• liquid line restrictions
• excessive refrigerant charge
Display
Codes 03 – Short Cycling
Diagnostic Description The ICC detects the run time for the last four (4) compressors or cycles that are less than three (3) min. each
Diagnostic Description The ICC detects the run time for the last four (4) compressors or cycles that are less than three (3) min. each
Possible Cause
• Check the thermostat wire connection
• Check thermostat location in the zone
• Check the thermostat wire connection
• Check thermostat location in the zone
Display
Codes L4 – Lock Rotor
Diagnostic Description ICC four (4) detects that there have been frequent guard trips and the average run time for each trip is less than 15 sec
Diagnostic Description ICC four (4) detects that there have been frequent guard trips and the average run time for each trip is less than 15 sec
Possible Cause
• bad run capacitor
• low line voltage
• excessive refrigerant in the compressor
• Seized Bearings in Compressor
• bad run capacitor
• low line voltage
• excessive refrigerant in the compressor
• Seized Bearings in Compressor
Display
Codes 05 – Open circuit (compressor will not runing)
Diagnostic Description ICC has traveled a guard for more than 4 hours
Diagnostic Description ICC has traveled a guard for more than 4 hours
Possible Cause
• Check for damaged, incorrect, or incorrect run capacitors
• Check for broken wires, loose connectors, or incorrect compressors
• Check the compressor winding for continuity
• Check for open compressor internal protector
• Check for damaged, incorrect, or incorrect run capacitors
• Check for broken wires, loose connectors, or incorrect compressors
• Check the compressor winding for continuity
• Check for open compressor internal protector
Display
Codes 06 – Compressor Open Start Circuit
Diagnostic Description ICC detects current in run circuit but not in start circuit of compressor
Diagnostic Description ICC detects current in run circuit but not in start circuit of compressor
Possible Cause
• Check for damaged, incorrect, or incorrect run capacitors
• Check for broken wires, loose connectors, or incorrect compressors
• Check the compressor winding for continuity
• Check for damaged, incorrect, or incorrect run capacitors
• Check for broken wires, loose connectors, or incorrect compressors
• Check the compressor winding for continuity
Display
Codes L6 – Compressor Open Start Circuit
Diagnostic Description ICC detects current in the run circuit but not in the start circuit of the compressor four (4) times in a compressor call
Diagnostic Description ICC detects current in the run circuit but not in the start circuit of the compressor four (4) times in a compressor call
Possible Cause
• Check for damaged, incorrect, or incorrect run capacitors
• Check for broken wires, loose connectors, or incorrect compressors
• Check the compressor winding for continuity
• Check for damaged, incorrect, or incorrect run capacitors
• Check for broken wires, loose connectors, or incorrect compressors
• Check the compressor winding for continuity
Display
Codes 07 – Compressor Open Run Circuit
Diagnostic Description ICC detects current in start circuit but not in run circuit of compressor
Diagnostic Description ICC detects current in start circuit but not in run circuit of compressor
Possible Cause
• Check for damaged, incorrect, or incorrect run capacitors
• Check for broken wires, loose connectors, or incorrect compressors
• Check the compressor winding for continuity
• Check for damaged, incorrect, or incorrect run capacitors
• Check for broken wires, loose connectors, or incorrect compressors
• Check the compressor winding for continuity
Display
Codes L7 – Compressor Open Run Circuit
Diagnostic Description The ICC detects the current in the start circuit but not four (4) times in a compressor call in the compressor’s run circuit
Diagnostic Description The ICC detects the current in the start circuit but not four (4) times in a compressor call in the compressor’s run circuit
Possible Cause
• Check for damaged, incorrect, or incorrect run capacitors
• Check for broken wires, loose connectors, or incorrect compressors
• Check the compressor winding for continuity
• Check for damaged, incorrect, or incorrect run capacitors
• Check for broken wires, loose connectors, or incorrect compressors
• Check the compressor winding for continuity
Display
Codes 09 – Low Secondary Voltage
Diagnostic Description Secondary voltage at R and C is below 18VoltAC
Diagnostic Description Secondary voltage at R and C is below 18VoltAC
Possible Cause
• control transformer overload
• low line voltage
• control transformer overload
• low line voltage
Display
Codes 21 – Low Pressure Control Open
Diagnostic Description ICC LPC detects open. Note: Low pressure control is ignored for the first 90 sec of compressor operation
Diagnostic Description ICC LPC detects open. Note: Low pressure control is ignored for the first 90 sec of compressor operation
Possible Cause
• Refrigerant charge in the unit is low
• Indoor coil is frozen (mode cooling)
• Dirty indoor coil or filter (mode cooling)
• Indoor blower is not running(mode cooling)
• Refrigerant charge in the unit is low
• Indoor coil is frozen (mode cooling)
• Dirty indoor coil or filter (mode cooling)
• Indoor blower is not running(mode cooling)
• External (outdoor)coil is frozen (heating
mode)
• Expansion valve is not working correctly
• Expansion valve is not working correctly
Display
Codes L21 flashing
Diagnostic Description Active Safety, Low Pressure Control Trip
Diagnostic Description Active Safety, Low Pressure Control Trip
Possible Cause
LPC has opened 3 times in the same cooling operation, ICC has locked the compressor to protect it. The ICC alternately flashes L and 21.
LPC has opened 3 times in the same cooling operation, ICC has locked the compressor to protect it. The ICC alternately flashes L and 21.
Display
Codes 27-
Diagnostic
Description low voltage or no voltage Error
Possible Cause
• Disconnect and check the incoming line voltage for the unit
• Check the wiring connection
• Disconnect and check the incoming line voltage for the unit
• Check the wiring connection
Display
Codes 28
Diagnostic Description High line voltage
Diagnostic Description High line voltage
Possible Cause
Fault check line voltage
Fault check line voltage
Display
Codes 29
Diagnostic Description High Pressure Control Open. ICC discovers that HPC is open
Diagnostic Description High Pressure Control Open. ICC discovers that HPC is open
Possible Cause
• External coils are dirty (mode cooling)
• Outdoor fan is not running (mode cooling)
• Dirty indoor coil or filter (mode heating)
• Indoor blower is not running (mode heating)
• liquid line restrictions
• excessive refrigerant charge
• External coils are dirty (mode cooling)
• Outdoor fan is not running (mode cooling)
• Dirty indoor coil or filter (mode heating)
• Indoor blower is not running (mode heating)
• liquid line restrictions
• excessive refrigerant charge
Display
Codes L29 Flashing – Active Protection
Diagnostic Description High pressure control trip
Diagnostic Description High pressure control trip
Possible Cause
LPC has opened 3 times in the same cooling operation, ICC has locked the compressor to protect it. ICC alternately flashes L and 29
LPC has opened 3 times in the same cooling operation, ICC has locked the compressor to protect it. ICC alternately flashes L and 29
Display
Codes 30 – Fuse Open
Diagnostic Description ICC discovers that on-board fuse is open
Diagnostic Description ICC discovers that on-board fuse is open
Possible Cause
• 3-amp fuse on ICC is open.
• Low voltage wiring on R and C is damaged or incorrect.
• 3-amp fuse on ICC is open.
• Low voltage wiring on R and C is damaged or incorrect.
Display
Codes 80 –
Diagnostic
Description Low Airflow
Possible Cause
The ICC detects that the indoor unit is not providing minimum airflow requirements.
Misapplied wrong indoor air mover – replace with properly sized machine.
The ICC detects that the indoor unit is not providing minimum airflow requirements.
Misapplied wrong indoor air mover – replace with properly sized machine.
Display
Codes 83 – Condenser Coil Temperature Defect
Diagnostic Description The sensor detects abnormally low or high coil temperatures
Diagnostic Description The sensor detects abnormally low or high coil temperatures
Possible Cause
• replace the sensor
• Check sensor control is installed correctly
• replace the sensor
• Check sensor control is installed correctly
Display
Codes 84 – Outdoor Ambient Temperature Defects
Diagnostic Description The sensor detects abnormally low or high outdoor ambient temperatures
Diagnostic Description The sensor detects abnormally low or high outdoor ambient temperatures
Possible Cause
• Check unit placement – If the outdoor unit is in a high temperature area, wait until the ambient temperature decreases and check the sensor readings.
• Replace the sensor.
• Check sensor control is installed correctly
• Check unit placement – If the outdoor unit is in a high temperature area, wait until the ambient temperature decreases and check the sensor readings.
• Replace the sensor.
• Check sensor control is installed correctly
Display
Codes 93 – Internal Control Defect
Diagnostic Description Control is not working properly.
Diagnostic Description Control is not working properly.
Possible Cause
• Check the controls for proper system operation.
• change control
• Check the controls for proper system operation.
• change control
Display
Codes d1
Diagnostic Description N0 shared data
Diagnostic Description N0 shared data
Possible Cause
Replace the memory card with the correct system information.
Replace the memory card with the correct system information.
Display
Codes D3 – Airflow CFM Mismatch
Diagnostic Description Indoor air movers (air handlers / furnaces) cannot supply the airflow required for proper system operation
Diagnostic Description Indoor air movers (air handlers / furnaces) cannot supply the airflow required for proper system operation
Possible Cause
Misplaced indoor air mower-replacement with incorrectly sized air handler / furnace.
Misplaced indoor air mower-replacement with incorrectly sized air handler / furnace.
Display
Codes d4 – (device) memory card invalid for device
Diagnostic Description The data in the memory card inserted into the control board does not match the data in the control.
Diagnostic Description The data in the memory card inserted into the control board does not match the data in the control.
Possible Cause
• Check the memory card to make sure it matches the device
• Check if a memory card is present
• Check the memory card to make sure it matches the device
• Check if a memory card is present
Display
Codes d8 – old shared data
Diagnostic
Description System data is obsolete
Possible
Cause If the system will not operate, order a new memory card to update
the system information.
