Fault Codes / Daikin

151 codes

Altherma

• 7H — Water flow malfunction – flow too low.
• 89 — Plate heat exchanger freezing.
• 8H — Outlet (flow) water temperature abnormally high.
• AA — Backup heater (BUH) overheated / BUH power cable not connected.
• AC — Booster heater (BSH) overheated.
• C0 — Flow sensor (flow switch) malfunction.
• E1 — Outdoor unit: PCB defect.
• E3 — Outdoor unit: high pressure switch (HPS) actuation.
• E5 — Inverter compressor overload or overheat.
• EC — DHW tank temperature abnormally high.
• F3 — Abnormal discharge pipe temperature.
• HJ — Water pressure sensor abnormality (HJ-10).
• U2 — Power supply malfunction / brief power failure.
• U3 — Screed dryout function not completed correctly.
• U4 — Transmission malfunction indoor/outdoor unit.
• U5 — Communication user interface (MMI) ↔ indoor fault.

VRV / Sky Air

• A0 — External protection device activated.
• A1 — Indoor unit PCB abnormality.
• A3 — Drain level / float switch activated.
• A5 — Freeze-up / high-pressure peak-cut at indoor coil.
• A6 — Indoor fan motor lock / overload.
• A6-01 — Indoor fan motor lock / overload.
• A6-11 — Indoor fan: position detection error.
• A7 — Swing flap motor fault.
• A8 — Indoor power supply voltage error.
• A9 — Electronic expansion valve (indoor) fault.
• AF — Malfunction of humidifier system (accessory).
• AJ — Capacity setting error (indoor).
• C1 — Failure of transmission between indoor unit PCB and sub PCB
• C4 — Liquid pipe thermistor (R2T) fault.
• C5 — Gas pipe thermistor (R3T) fault.
• C6 — Malfunction of fan motor sensor or fan control driver
• C7 — Front panel / flap drive motor (position sensor) fault.
• C9 — Suction air thermistor (R1T) fault.
• CA — Malfunction of discharge air thermistor
• CC — Humidity sensor fault.
• CJ — Remote controller thermistor fault.
• E0 — Protection device activated (general).
• E1 — Outdoor PCB faulty.
• E2 — E2 = current leakage detected in the earth-leakage detection circuit (triggers when leakage current is sensed). Causes: earth fault (defective wiring or current sensor), defective compressor insulation (or insulation of other parts), or temporary liquid back / refrigerant stagnation.
• E3 — High pressure switch (HPS) actuation.
• E3-02 — High pressure: overcharge or closed stop valve.
• E3-13 — Actuation of high pressure switch during test run.
• E4 — Low-pressure protection / LP sensor (suction below threshold).
• E5 — Inverter compressor overload / motor lock.
• E5-01 — Inverter compressor 1 lock.
• E5-02 — Compressor startup overload (constant compressor).
• E5-07 — Inverter compressor 2 lock.
• E6 — Standard compressor lock / startup / overcurrent fault.
• E6-01 — Compressor startup failure — motor stalls immediately.
• E7 — Outdoor fan motor fault / lock.
• E7-01 — Outdoor fan motor 1 lock.
• E7-02 — Outdoor fan motor 2 lock/overload.
• E7-05 — Outdoor fan motor: momentary overcurrent.
• E7-09 — Outdoor fan motor: IPM error (fan PCB).
• E8 — Overcurrent of inverter compressor.
• E9 — Electronic expansion valve (outdoor) fault.
• E9-01 — Electronic expansion valve (Y1E) error.
• E9-02 — EXV 2 — coil short.
• E9-20 — Defective EXV coil (Y1E).
• EA — 4-way valve / cool-heat switchover fault.
• F3 — Discharge pipe temperature too high.
• F6 — Abnormal high pressure in cooling (overcharge).
• H0 — H0 = malfunction of the compressor sensor system (general) — caused by disconnected/defective harness or a defective PCB, NOT specifically a voltage/current sensor fault. Applies only to RA and Chiller units (not VRV/SkyAir/Package/Fan Coil).
• H1 — Malfunction of room temperature sensor or humidifier unit damper
• H3 — High pressure switch (HPS) itself faulty.
• H3-01 — High pressure switch HPS1 tripped (circuit 1).
• H3-02 — Harness abnormality (main & inverter PCB).
• H4 — Low pressure switch (LPS) actuation.
• H5 — Compressor overload sensor fault.
• H6 — Position detection / compressor startup failure.
• H7 — Outdoor fan motor: position signal abnormality.
• H8 — Compressor input (CT) system fault.
• H9 — Outdoor air thermistor (R1T) fault.
• HF — Alarm in thermal storage unit or storage controller
• J0 — J0 = thermistor miswiring (installation/wiring defect), NOT a generic refrigerant-temperature-sensor malfunction. Sensor-itself failures are covered by J3/J4/J5/J6/J7/J8/J9.
• J1 — Pressure sensor fault.
• J2 — Current sensor (CT) fault.
• J3 — Discharge pipe thermistor fault.
• J3-01 — Discharge sensor R2T (compressor 1) open.
• J3-16 — Discharge pipe thermistor (R31T): open circuit.
• J3-17 — Discharge pipe thermistor (R31T): short circuit.
• J4 — Malfunction of low pressure equivalent saturated temperature sensor system.
• J5 — Suction pipe thermistor fault.
• J6 — Heat exchanger (deicer) thermistor fault.
• J6-01 — Heat exchanger (deicer) thermistor fault.
• J7 — Subcooling heat exchanger liquid thermistor fault.
• J7-01 — Liquid pipe sensor R5T open.
• J7-06 — Subcooling liquid pipe thermistor fault.
• J8 — Liquid pipe / subcooling thermistor fault.
• J8-01 — Heat exchanger liquid thermistor (R4T) fault.
• J9 — Subcooling heat exchanger gas thermistor fault.
• JA — High pressure sensor (S1NPH) fault.
• JA-06 — High pressure sensor (S1NPH): open circuit.
• JA-07 — High pressure sensor (S1NPH): short circuit.
• JC — Low pressure sensor fault.
• JC-06 — Low pressure sensor: open circuit.
• JC-07 — Low pressure sensor: short circuit.
• JE — Malfunction of oil pressure sensor or sub-tank thermistor
• L0 — Inverter system malfunction (general).
• L1 — Inverter PCB (INV) fault.
• L1-01 — IPM error (compressor M1C).
• L1-04 — IGBT error (compressor M1C).
• L1-05 — Jumper setting error (inverter ↔ compressor 1).
• L1-17 — Instantaneous overcurrent (inverter compressor 2).
• L3 — Electrical box temperature rise.
• L4 — Inverter heat sink (fin) temperature rise.
• L4-01 — Inverter heat sink temperature too high.
• L5 — Inverter compressor instantaneous overcurrent (output overcurrent).
• L5-01 — Inverter compressor startup overcurrent.
• L6 — Inverter instantaneous overcurrent (AC output)
• L8 — Inverter overcurrent / electronic thermal protection.
• L8-01 — Compressor sustained overcurrent.
• L9 — Compressor lock prevention (startup/stall protection).
• L9-01 — Compressor stalled — mechanical.
• LC — Communication inverter ↔ control (outdoor) fault.
• M1 — Malfunction of central remote controller PCB
• MA — Improper combination of optional controllers for centralized control
• MC — Address duplication, improper setting
• P0 — Shortage of refrigerant amount (thermal storage unit)
• P1 — Open phase / power supply imbalance.
• P1-01 — Inverter voltage fluctuation — phase imbalance.
• P2 — Automatic refrigerant charge operation stop
• P3 — Control box thermistor / abnormal direct current.
• P4 — Radiating fin temperature sensor fault.
• P4-01 — Inverter heat sink thermistor fault.
• P9 — Automatic refrigerant charge operation completed
• PA — Refrigerant cylinder during automatic refrigerant charging (master unit empty)
• PC — Refrigerant cylinder during automatic refrigerant charging (slave unit 2 empty)
• PE — Automatic refrigerant charge operation nearly completed
• PH — Refrigerant cylinder during automatic refrigerant charging
• PJ — Capacity setting mismatch (outdoor).
• U0 — Refrigerant shortage (low pressure / stop valve closed).
• U0-01 — Refrigerant shortage detected (low suction pressure).
• U1 — Reverse phase / open phase (rotation).
• U2 — Power supply defect / brief power failure.
• U2-01 — Supply voltage too low.
• U2-02 — Supply voltage too high.
• U4 — Transmission error indoor/outdoor unit.
• U4-01 — Indoor ↔ outdoor communication error — wiring.
• U5 — Communication indoor ↔ remote controller fault.
• U5-01 — Communication error remote ↔ indoor.
• U7 — Communication between outdoor units / main-INV CPU fault.
• U8 — Communication main/sub remote controllers fault.
• U9 — Communication fault with other units in the same system.
• UA — Indoor/outdoor mismatch (installation/field setting).
• UC — Centralized address duplication.
• UE — Communication indoor ↔ centralized controller fault.
• UF — System is not set yet (commissioning incomplete).
• UH — UH = 'malfunction of system' (system-level fault) caused by improper transmission wiring between units or a defective PCB. It is NOT 'refrigerant system address undetermined' — that belongs to code UF.
• UJ — Malfunction of transmission (accessory device)