Rinnai Air Conditioner Fault Codes: Split, Ducted and Mini VRF Guide

Code: A01 means emergency stop.
What to do: Leave the system off and determine whether an emergency switch, fire system or central controller has stopped it. Do not restart it until the reason is known.

Code: A11 means a R32 refrigerant leak detected, where an R32 leak-detection configuration is fitted; the system shuts down.
What to do: Leave the system off, ventilate the area, avoid flames or ignition sources and arrange urgent service by a licensed refrigerant technician.

Code: A51 is an outdoor unit fault; inspect the outdoor display for the underlying code.
What to do: Check the display on the outdoor unit, if it can be viewed safely, and record its code. A technician will need the outdoor code to identify the underlying fault.

Code: A71 / A73 is an interlocked heat-recovery ventilation unit fault in series / non-series configuration.
What to do: Arrange service for the connected heat-recovery ventilation equipment and its communication circuit.

Code: A72 is a humidity unit fault.
What to do: The humidity-control equipment needs professional inspection.

Code: A74 is an AHU kit slave fault.
What to do: Arrange service. The AHU interface, addressing or connected equipment may require testing.

Code: A81 is a self-check fault.
What to do: Allow any commissioning test to finish. If the code remains, arrange technician diagnosis.

Code: A82 is a refrigerant flow-direction switching-device fault.
What to do: Leave the affected system off and book service. The valve, actuator or control circuit requires testing.

Code: A91 is an operating-mode conflict.
What to do: Check whether connected indoor units are requesting incompatible modes. Set them to the same compatible mode or follow the building’s central-control settings.

Code: b11 / b13 is an electronic expansion valve No. 1 / No. 2 coil fault.
What to do: Arrange service. These codes concern the expansion-valve coils or valve bodies and are not user-serviceable.

Code: b12 / b14 is an electronic expansion valve No. 1 / No. 2 body fault.
What to do: Arrange service. These codes concern the expansion-valve coils or valve bodies and are not user-serviceable.

Code: b34 / b35 is a water-pump No. 1 / No. 2 protection.
What to do: Turn the affected indoor unit off and check for visible water. Arrange prompt service for the drain and pump system.

Code: b36 is a water-level switch alarm.
What to do: Turn the affected unit off immediately, particularly if water is dripping or appearing at a safety drain. The drain, pump or float switch needs inspection.

Code: b71 / b72 is a reheating / pre-processing electric-heater fault.
What to do: Leave the affected heating function off and arrange electrical diagnosis.

Code: b81 is a humidifier fault.
What to do: Stop using the humidification function and arrange service.

Code: C11 means duplicate indoor-unit address.
What to do: This is a commissioning or addressing problem. A VRF technician must identify and correct the duplicate address.

Code: C21 is an indoor/outdoor communication fault.
What to do: Check whether an indoor or outdoor unit has been deliberately isolated. If not, arrange service to test power, communication wiring and control boards.

Code: C41 is a communication fault between indoor main board and fan-drive board.
What to do: Turn the affected unit off and arrange service.

Code: C51 is a communication fault between indoor unit and wired controller.
What to do: Record whether the controller is blank, intermittent or showing other codes, then arrange service. Do not remove the controller from the wall.

Code: C52 is a communication fault between indoor unit and Wi-Fi kit.
What to do: Check that the router and Wi-Fi equipment are operating. If normal controller operation is also affected or the code remains, arrange service.

Code: C61 is a communication fault between indoor main board and display board.
What to do: Arrange service. The display, internal wiring or control board requires testing.

Code: C71 is a communication fault between AHU slave and master.
What to do: C71-79 are communication or configuration faults involving AHU fresh-air, humidification, expansion or controller equipment. Record the exact code and arrange specialist VRF service. These faults involve linked components, addressing or internal communication wiring.

Code: C72 is an AHU kit quantity mismatch
What to do: C71-79 are communication or configuration faults involving AHU fresh-air, humidification, expansion or controller equipment. Record the exact code and arrange specialist VRF service. These faults involve linked components, addressing or internal communication wiring.

Code: C73 is a communication fault between a linked humidifying indoor unit and master unit
What to do: C71-79 are communication or configuration faults involving AHU fresh-air, humidification, expansion or controller equipment. Record the exact code and arrange specialist VRF service. These faults involve linked components, addressing or internal communication wiring.

Code: C74 / C75 is a communication fault between linked fresh-air processing unit and master unit, in series / non-series configuration
What to do: C71-79 are communication or configuration faults involving AHU fresh-air, humidification, expansion or controller equipment. Record the exact code and arrange specialist VRF service. These faults involve linked components, addressing or internal communication wiring.

Code: C76 is a communication fault between main and secondary wired controllers
What to do: C71-79 are communication or configuration faults involving AHU fresh-air, humidification, expansion or controller equipment. Record the exact code and arrange specialist VRF service. These faults involve linked components, addressing or internal communication wiring.

Code: C77 / C78 is a communication fault between indoor board and expansion board No. 1 / No. 2
What to do: C71-79 are communication or configuration faults involving AHU fresh-air, humidification, expansion or controller equipment. Record the exact code and arrange specialist VRF service. These faults involve linked components, addressing or internal communication wiring.

Code: C79 is a communication fault between indoor board and switch board
What to do: C71-79 are communication or configuration faults involving AHU fresh-air, humidification, expansion or controller equipment. Record the exact code and arrange specialist VRF service. These faults involve linked components, addressing or internal communication wiring.

Code: C81 is an indoor unit power-off fault.
What to do: Check whether that indoor unit’s power has been deliberately isolated. If a breaker has tripped, do not repeatedly reset it; arrange electrical diagnosis.

Code: d16 is an inlet temperature too low during heating.
What to do: Check whether doors, windows or fresh-air dampers are allowing unusually cold air into the system. If conditions are normal or the code returns, arrange service.

Code: d17 is an inlet temperature too high during cooling.
What to do: Reduce unusual heat entering the conditioned area and check for obstructed return airflow. Persistent codes need professional diagnosis.

Code: d81 is a temperature or humidity outside the permitted range fault.
What to do: Allow indoor conditions to return to the system’s normal operating range. Arrange service if the code appears under ordinary conditions.

Code: dE1 is a sensor control-board fault. Arrange a service.
What to do: dE1 is a sensor control-board fault. Arrange a service.

Code: dE2 is a PM2.5 sensor fault
What to do: dE2, dE3, dE4 or dE5 are all indoor air-quality or occupancy sensor faults: Cooling and heating may continue without the affected feature. Arrange service if the code remains or air-quality controls are required.

Code: dE3 is a CO2 sensor fault
What to do: dE2, dE3, dE4 or dE5 are all indoor air-quality or occupancy sensor faults: Cooling and heating may continue without the affected feature. Arrange service if the code remains or air-quality controls are required.

Code: dE4 is a Formaldehyde sensor fault
What to do: dE2, dE3, dE4 or dE5 are all indoor air-quality or occupancy sensor faults: Cooling and heating may continue without the affected feature. Arrange service if the code remains or air-quality controls are required.

Code: dE5 is a human-detection sensor fault
What to do: dE2, dE3, dE4 or dE5 are all indoor air-quality or occupancy sensor faults: Cooling and heating may continue without the affected feature. Arrange service if the code remains or air-quality controls are required.

Code: E21 is a fresh-air inlet temperature sensor T0 open or short circuit.
What to do: E21 to E24 are all fresh-air, dry-bulb or return-air temperature sensor faults: Arrange service to test the specified sensor and its wiring.

Code: E22 / E23 is upper / lower dry-bulb temperature sensor open or short circuit.
What to do: E21 to E24 are all fresh-air, dry-bulb or return-air temperature sensor faults: Arrange service to test the specified sensor and its wiring.

Code: E24 is an indoor return-air temperature sensor T1 open or short circuit.
What to do: E21 to E24 are all fresh-air, dry-bulb or return-air temperature sensor faults: Arrange service to test the specified sensor and its wiring.

Code: E31 is a wired-controller room-temperature sensor fault.
What to do: E31, E32 or E33 are all controller, wireless or external room-temperature sensor faults. Check whether a wireless sensor needs batteries, where applicable. Otherwise, arrange service.

Code: E32 is a wireless temperature-sensor fault.
What to do: E31, E32 or E33 are all controller, wireless or external room-temperature sensor faults. Check whether a wireless sensor needs batteries, where applicable. Otherwise, arrange service.

Code: E33 is an external room-temperature sensor fault.
What to do: E31, E32 or E33 are all controller, wireless or external room-temperature sensor faults. Check whether a wireless sensor needs batteries, where applicable. Otherwise, arrange service.

Code: E61 / E62 is a pre-cooled / pre-heated fresh-air temperature sensor fault.
What to do: Arrange service. These sensors are within the controlled air-handling system.

Code: E81 is an outlet-air temperature sensor TA fault.
What to do: Arrange service. These sensors are within the controlled air-handling system.

Code: EA1 / EA2 is an outlet / return-air humidity sensor fault.
What to do: Arrange service if humidity or fresh-air control is affected.

Code: EA3 / EA4 is an upper / lower wet-bulb sensor fault.
What to do: Arrange service if humidity or fresh-air control is affected.

Code: EC1 is an R32 refrigerant leak-sensor fault, where fitted.
What to do: Leave the affected system off and arrange prompt service. The leak-detection safety system may not be operating reliably.

Code: F01 is a heat-exchanger inlet temperature sensor T2A fault.
What to do: Arrange service to test the sensor and wiring.

Code: F11 is a heat-exchanger middle temperature sensor T2 fault.
What to do: Arrange service to test the sensor and wiring.

Code: F21 is a heat-exchanger outlet temperature sensor T2B fault.
What to do: Arrange service to test the sensor and wiring.

Code: F12 is a T2 over-temperature protection.
What to do: Turn the affected unit off and check that filters, return grilles and supply outlets are not blocked. If the code returns, book service.

Code: P31 is a fan-drive board input over-current protection.
What to do: Leave the affected unit off and arrange electrical and fan-motor diagnosis.

Code: P34 means P31 occurred at least six times within 60 minutes.
What to do: This means the fan protection has operated several times. Do not restart the unit; arrange service.

Code: P52 means the supply voltage is too low.
What to do: If there has been a local power problem, wait until the supply is stable. If the code returns, arrange electrical and VRF system checks.

Code: P71 / P72 is a main-control / display-control EEPROM fault.
What to do: Arrange service. The board settings, programming or hardware may require attention.

Code: U01 is an electronic lock active.
What to do: Check the central controller or speak with the building manager. This may be a control restriction rather than an equipment failure.

Code: U11 is a unit model code not set error
What to do: U11-U15 above are commissioning settings. A VRF technician must confirm the equipment selections and control-board settings.

Code: U12 is a capacity/horsepower code not set error
What to do: U11-U15 above are commissioning settings. A VRF technician must confirm the equipment selections and control-board settings.

Code: U14 is a capacity/horsepower setting error
What to do: U11-U15 above are commissioning settings. A VRF technician must confirm the equipment selections and control-board settings.

Code: U15 is a AHU fan-control input or DIP-switch setting error
What to do: U11-U15 above are commissioning settings. A VRF technician must confirm the equipment selections and control-board settings.

Code: U38 is an address not detected error.
What to do: Arrange service to check addressing, communication wiring and commissioning settings.

Code: J01 means the fan motor has failed repeatedly.
What to do: All J codes are fan motor, drive module or electrical fault codes. Leave the affected indoor unit off and arrange service. Do not attempt to turn or access the fan manually.

Code: J1E means the fan module/IPM over-current
What to do: All J codes are fan motor, drive module or electrical fault codes. Leave the affected indoor unit off and arrange service. Do not attempt to turn or access the fan manually.

Code: J11 means instantaneous phase-current over-current
What to do: All J codes are fan motor, drive module or electrical fault codes. Leave the affected indoor unit off and arrange service. Do not attempt to turn or access the fan manually.

Code: J3E / J31 means DC bus voltage too low / too high
What to do: All J codes are fan motor, drive module or electrical fault codes. Leave the affected indoor unit off and arrange service. Do not attempt to turn or access the fan manually.

Code: J43 means phase-current sampling bias fault
What to do: All J codes are fan motor, drive module or electrical fault codes. Leave the affected indoor unit off and arrange service. Do not attempt to turn or access the fan manually.

Code: J45 is a motor and indoor-unit mismatch
What to do: All J codes are fan motor, drive module or electrical fault codes. Leave the affected indoor unit off and arrange service. Do not attempt to turn or access the fan manually.

Code: J47 is an IPM and indoor-unit mismatch
What to do: All J codes are fan motor, drive module or electrical fault codes. Leave the affected indoor unit off and arrange service. Do not attempt to turn or access the fan manually.

Code: J5E is a motor start fault
What to do: All J codes are fan motor, drive module or electrical fault codes. Leave the affected indoor unit off and arrange service. Do not attempt to turn or access the fan manually.

Code: J52 is a motor blocked
What to do: All J codes are fan motor, drive module or electrical fault codes. Leave the affected indoor unit off and arrange service. Do not attempt to turn or access the fan manually.

Code: J55 is a speed-control mode setting error
What to do: All J codes are fan motor, drive module or electrical fault codes. Leave the affected indoor unit off and arrange service. Do not attempt to turn or access the fan manually.

Code: J6E is a motor phase-loss fault
What to do: All J codes are fan motor, drive module or electrical fault codes. Leave the affected indoor unit off and arrange service. Do not attempt to turn or access the fan manually.

Code: The b36 water-level alarm, A11 refrigerant-leak shutdown and recurring electrical protection codes should be treated promptly. A licensed technician may need to inspect the condensate system, leak-detection circuit, refrigerant circuit or electrical supply.
What to do: The b36 water-level alarm, A11 refrigerant-leak shutdown and recurring electrical protection codes should be treated promptly. A licensed technician may need to inspect the condensate system, leak-detection circuit, refrigerant circuit or electrical supply.

Mini VRF outdoor-unit codes

Code: HF means the incorrect type of indoor unit is connected
What to do: This is an equipment compatibility or commissioning issue. Arrange specialist VRF service from our team at ExtrordinAir.

Code: H0 is a communication fault between the main control and motor-drive modules.
What to do: Leave the system off and arrange service.

Code: H4 means that L0 or L1 has occurred three times within one hour.
What to do: Do not continue resetting the system. A technician must diagnose the repeated L0 or L1 events.

Code: H7 means the number of detected indoor units has changed from the configured number.
What to do: Check whether any indoor units have been deliberately isolated. Otherwise, arrange service to inspect power, addressing and communication wiring.

Code: E2 is a communication fault between indoor and outdoor units.
What to do: Check whether any unit has been switched off or isolated. If all units should have power, arrange service.

Code: E3 means a T6A or T6B temperature-sensor fault.
What to do: Arrange service to test the specified sensor and wiring.

Code: E4 means the T3 condenser or T4 outdoor ambient temperature-sensor has a fault.
What to do: Turn the system off. If the problem follows a supply interruption, wait until power is stable before one restart. Recurring faults need electrical testing.

Code: E5 is an input-voltage fault.
What to do: Turn the system off. If the problem follows a supply interruption, wait until power is stable before one restart. Recurring faults need electrical testing.

Code: E6 is a DC fan fault.
What to do: Turn the system off and check only for obvious debris around the fan guard. Do not remove the guard or touch the fan.

Code: Eb means E6 (DC fan fault) has occurred more than six times in one hour.
What to do: Leave the system off and book service. The fan protection has operated multiple times.

Code: E9 is a compressor parameter mismatch; shown as E.9. on some displays.
What to do: Arrange specialist diagnosis. Compressor or inverter settings may be incorrect.

Code: EF is a power-factor-correction fault.
What to do: Leave the system off and arrange electrical service.

Code: EH is a refrigerant-radiator temperature-sensor fault.
What to do: Arrange service. Do not access the outdoor electrical compartment.

Code: PL is a refrigerant-radiator surface-temperature fault.
What to do: Arrange service. Do not access the outdoor electrical compartment.

Code: P1 is a high-pressure protection fault.
What to do: Turn the system off and check for obvious airflow obstructions around the outdoor unit. If the area is clear, leave it off and book service.

Code: P2 is a low-pressure protection fault.
What to do: Leave the system off and arrange a licensed refrigerant technician. Possible causes include a leak, restriction or pressure-control fault.

Code: P3 is an over-current protection fault.
What to do: Turn the system off and arrange electrical and compressor diagnosis.

Code: P4 is a compressor discharge-temperature T5 protection fault.
What to do: Leave the system off and book service. Repeated operation could place further stress on the compressor.

Code: P5 is a condenser-temperature T3 protection fault .
What to do: Check that the outdoor unit has clear airflow. If the code remains or returns, arrange service.

Code: P8 is a strong-wind/typhoon protection code.
What to do: Wait for severe wind conditions to pass and allow the system to recover. If the code appears in calm weather, arrange service.

Code: P9 is a reversing-valve changeover fault.
What to do: Arrange service. The valve, control circuit and refrigerant operation require testing.

Code: PE is an indoor evaporator-temperature T2 protection code.
What to do: Check filters, return-air grilles and supply outlets for restrictions. Persistent codes require professional diagnosis.

Code: L0 is a compressor IPM module protection code.
What to do: Leave the system off and arrange service.

Code: L1 is a DC bus low-voltage protection code .
What to do: Wait for the electrical supply to stabilise after any local outage. If the code returns, arrange electrical testing.

Code: L2 is a DC bus high-voltage protection code.
What to do: Turn the system off and arrange service.

Code: L4 is a software over-current protection code.
What to do: Leave the system off and arrange compressor and inverter diagnosis.

Code: L5 is a compressor zero-speed protection code.
What to do: Book service. The compressor has not operated as commanded.

Code: L7 is a compressor phase-sequence error code.
What to do: Leave the system off and arrange professional electrical diagnosis.

Code: L8 is a compressor speed changed by more than 15 Hz within one second code
What to do: Stop repeated restart attempts and arrange service for both L8 and L9 codes.

Code: L9 means the difference between requested and actual compressor speed exceeds 15 Hz
What to do: Stop repeated restart attempts and arrange service for both L8 and L9 codes.

Code: F1 means the DC bus remained below 200 V DC for five seconds after compressor start-up
What to do: Arrange electrical and inverter diagnosis.

Code: PF means the outdoor unit is locked.
What to do: Contact the installer or service technician. This may be a commissioning, protection or service-control lock.

Code: PH is a refrigerant-radiator sensor or low-temperature protection code .
What to do: The system may recover when outdoor conditions improve. If the code remains in normal conditions, arrange service.

Code: Most outdoor Mini VRF codes are technician-level diagnostics. The code identifies the protection circuit that stopped the system; it does not, by itself, prove which part should be replaced. Refrigerant pressures, temperatures, electrical readings, addressing and service history must be tested before a repair decision is made.
What to do: Most outdoor Mini VRF codes are technician-level diagnostics. The code identifies the protection circuit that stopped the system; it does not, by itself, prove which part should be replaced. Refrigerant pressures, temperatures, electrical readings, addressing and service history must be tested before a repair decision is made.