Rheem Heat Pump Error Codes


Two-Stage Heat Pump Outdoor Units – R410a
(-)Prl-Jec 16 Seer Equipped With The Comfort Control2 System™

0 – Standby
No command for unit operation
Normal operation

c – First Stage Cooling
Unit has received a command for first stage cooling
Normal operation

c(flashing) – Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) active
• The unit has received a command for first stage cooling during an active anti-short cycle timer or minimum run timer.
• Wait until unit timer has expired or press the TEST button to defeat short cycle delay.

C – Second Stage Cooling
Unit has received a command for second stage cooling
Normal operation

C(flashing) – Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) active
• The unit has received a command for second stage cooling during an active anti-short cycle timer or minimum run timer.
• Wait unit timer has expired or press the TEST button to defeat short cycle delay.

h – First Stage Heat Pump, Unit has received a command for first stage heat pump
Normal operation

h(flashing) – Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) active
• The unit has received a command for first stage heat pump during an active anti-short cycle timer or minimum run timer.
• Wait unit timer has expired or press the TEST button to defeat short cycle delay.

H – Second Stage Heat Pump, Unit has received a command for second stage heat pump
Normal operation

H(flashing) – Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) active
• The unit has received a command for second stage heat pump during an active anti-short cycle timer or minimum run timer.
• Wait unit timer has expired or press the TEST button to defeat short cycle delay.

d – Defrost Active, The unit is undergoing a defrost cycle
Normal operation

t – Test Mode
The ICC is in TEST mode

P – Protector Trip
A command for compressor operation is present but no current is measured to the compressor
• Motor protector open

01 – Long Run Time (Compressor)
The compressor has continuously run for more than 18 hours in the cooling mode.
• Low refrigerant charge
• Air ducts have substantial leakage
• Dirty indoor air filter
• Dirty outdoor coil

02 – High Side Fault
Compressor limit has opened four (4) times within a call for operation
• Outdoor fan is not running (cooling mode)
• Dirty indoor coil or filter (heating mode)
• Indoor blower is not running (heating mode)
• Liquid line restriction
• Excessive refrigerant charge




03 – Short Cycling
The ICC detects the run time for the past four (4) compressor cycles is less than three (3) minutes each.
• Check thermostat wire connections (R, C, 1, &,2)
• Check thermostat location in zone (too close to discharge grill)
L4 – Locked Rotor
The ICC detects four (4) consecutive protector trips have occurred and the average run time for each trip is less than 15 seconds.
• Bad run capacitor
• Low line voltage
• Excessive refrigerant in compressor
• Seized bearings in compressor
05 – Open Circuit (Compressor will not Run)
• The ICC has had a protector trip for longer than 4 hours.
• Check for damaged, miswired, or wrong run capacitor
• Check for broken wires, loose connectors, or miswired compressor
• Check compressor windings for continuity
• Check for open compressor internal protector
06 – Compressor Open Start Circuit
• Check for damaged, miswired, or wrong run capacitor
• Check for broken wires, loose connectors, or miswired compressor
• Check compressor windings for continuity
L6 – Compressor Open Start Circuit
• Check for damaged, miswired, or wrong run capacitor
• Check for broken wires, loose connectors, or miswired compressor
• Check compressor windings for continuity
07 – Compressor Open Run Circuit
• Check for damaged, miswired, or wrong run capacitor
• Check for broken wires, loose connectors, or miswired compressor
• Check compressor windings for continuity
L7 – Compressor Open Run Circuit
• Check for damaged, miswired, or wrong run capacitor
• Check for broken wires, loose connectors, or miswired compressor
• Check compressor windings for continuity

09 – Low Secondary Volts
• Control transformer overloaded
• Low line voltage
21 – Low Pressure Control Open
• Unit has low refrigerant charge
• Indoor coil is frozen (cooling mode)
• Dirty indoor coil or filter (cooling mode)
• Indoor blower is not running (cooling mode)
• Outdoor coil is frozen (heating mode)
• Expansion valve is not operating correctly
L21 – Active Protection Low Pressure
• LPC has opened 3 times in the same cooling operation, the ICC has locked out the compressor to protect it. ICC alternately flashes L and 21
27 – Low Line Voltage or No Line Voltage Fault
• Check incoming line voltage to the disconnect and unit
• Check wiring connections
28 – High Line Voltage Fault
• Check line voltage
29 – High Pressure Control Open, The ICC detects the HPC is open
• Outdoor coil is dirty (cooling mode)
• Outdoor fan is not running (cooling mode)
• Dirty indoor coil or filter (heating mode)
• Indoor blower is not running (heating mode)
L29 – Active Protection High Pressure Control Trip
LPC has opened 3 times in the same cooling operation, the ICC has locked out the compressor to protect it. ICC alternately flashes L and 29
30 – Fuse Open
• The 3-amp fuse on the ICC is open.
• Low voltage wiring at R and C is damaged or miswired
80 – Low Air Flow
• Misapplied/wrong indoor air mover –replace with properly sized unit.
84 – Outdoor Ambient Temperature Fault
• Check sensor is installed correctly on control
90 – Communication Fault
• Check control for proper system operation
d1 – No Shared Data
• Replace memory card with correct system information.
d8 – Old Shared Data
• If system will not operate, order new memory card to update system information.








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