Viessmann · A major brand in the UK. 694 codes across 4 product families, each taken from the manufacturer’s manuals. Viessmann technical support ↗
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694 codes
| Code | Meaning | Stops? | Homeowner check? |
|---|---|---|---|
| 0A | Short circuit/lead break, low pressure sensor | Yes | Yes |
| 0B | Short circuit/lead break, secondary circuit flow temperature sensor in the appliance | Yes | Yes |
| 0C | External unit: No functional impairment | No | Yes |
| 0D | Short circuit/lead break, coding resistor | Yes | Yes |
| 0E | Short circuit/lead break, suction gas temperature sensor (downstream of evaporator) | Yes | Yes |
| 0F | Short circuit/lead break liquid gas temperature sensor (downstream of condenser) | Yes | Yes |
| 01 | Short circuit/lead break, air intake temperature sensor | Varies by model | Yes |
| 1A | Safety chain interrupted, compressor blocked | Yes | Yes |
| 1E | EEV PCB faulty | Yes | Yes |
| 1F | Parameter "Output compressor stage 5030" not set correctly | Yes | Yes |
| 02 | Short circuit/lead break, air discharge temperature sensor | Partly | Yes |
| 2A | Inverter power consumption too high | Yes | Yes |
| 2B | Max. suction gas pressure exceeded | Yes | Yes |
| 2C | Min. pressure differential between high and low pressure side has not been reached. | Yes | Yes |
| 2D | Compression ratio too low | Yes | Yes |
| 2E | Min. required high pressure undershot | Yes | Yes |
| 2F | Min. required evaporation pressure undershot | Yes | Yes |
| 03 | Short circuit/lead break suction gas temperature sensor | Varies by model | Yes |
| 3A | Safety high pressure switch has responded. | Varies by model | Yes |
| 3B | Hot gas temperature: Compressor may shut down as a result of changed refrigerant circuit conditions (only heat pumps without electronic expansion valve). | Not stated | Yes |
| 3C | Hot gas temperature 2: Compressor heat pump stage 2 may shut down as a result of changed refrigerant circuit conditions (only heat pumps without electronic expansion valve). | Not stated | Yes |
| 3D | Evaporator sensor 2: The air discharge temperature sensor is used for defrosting the evaporator. | Partly | Yes |
| 04 | Short circuit/lead break, hot gas temperature sensor | Varies by model | Yes |
| 4A | Evaporation temperature too low | No | Yes |
| 4B | EEV connecting cable faulty; EEV stepper motor faulty | Not stated | Yes |
| 4C | Suction gas superheating too high | Varies by model | Yes |
| 4D | Coolant buff fl t sens: No cooling operation with coolant buffer cylinder. | Partly | Yes |
| 05 | Short circuit/lead break, high pressure sensor | Varies by model | Yes |
| 5A | Electronic expansion valve for refrigerant collector level control faulty | Varies by model | Yes |
| 5B | Charge level in refrigerant collector too low | No | Yes |
| 5C | Cylinder sensor solar: No solar DHW heating with Vitosolic 200. Solar circuit pump stays switched off. | Yes | Yes |
| 5D | Insufficient hot gas superheating | Yes | Yes |
| 5F | Communication error for the following temperature sensors: Reversible suction gas; temperature sensor Secondary circuit flow; temperature sensor (upstream of instantaneous heating water heater) Liquid gas temperature; sensor | Yes | Yes |
| 06 | Short circuit/lead break liquid gas temperature sensor 1 (upstream of the EEV) | Yes | Yes |
| 6A | Air intake temperature too low | Not stated | Yes |
| 6B | Air intake temperature too high | Not stated | Yes |
| 6C | Secondary circuit flow temperature too high | Not stated | Yes |
| 6D | Central cooling: Secondary circuit flow temperature too low | Not stated | Yes |
| 6E | Defrosting: Secondary circuit flow temperature too low | Partly | Yes |
| 6F | Compressor speed below min. speed for 90 s | Yes | Yes |
| 07 | Short circuit/lead break liquid gas temperature sensor 2 (downstream of the EEV) | Not stated | Yes |
| 7A | Room temp. sensor HC3: No frost protection mode via room temperature sensor; No room temperature hook-up; No room temperature-dependent control | Not stated | Yes |
| 7B | Room temp. sensor SKK: No cooling mode | Partly | Yes |
| 08 | Short circuit/lead break, secondary circuit return temperature sensor | Partly | Yes |
| 8A | Internal inverter fault | Yes | Yes |
| 8B | Internal inverter fault | Yes | Yes |
| 8C | Communication error | Yes | Yes |
| 8D | Short circuit/lead break, inverter temperature sensor | Yes | Yes |
| 8E | "Autotuning" function deactivated | No | Yes |
| 8F | Compressor drive deactivated | Yes | Yes |
| 09 | Short circuit/lead break evaporator temperature sensor | Varies by model | Yes |
| 9A | Supply voltage of inverter control outside of voltage range | Yes | Yes |
| 9B | Vitocal 300-G/333-G: Temperature of power factor correction filter too high | Varies by model | Yes |
| 9C | Outside temperature too low | Yes | Yes |
| 9D | Temperature differential of phase controls too high | Yes | Yes |
| 9E | 1 phase of inverter supply voltage missing. | Yes | Yes |
| 9F | More than 10 messages have occurred | Yes | Yes |
| 10 | Compressor has stopped. | Varies by model | Yes |
| 10/11 | Compressor has stopped. | Yes | Yes |
| 12 | Inverter fault (general message) | Not stated | Yes |
| 13 | Communication error | Yes | Yes |
| 15 | Inverter and compressor incompatible | Yes | Yes |
| 16 | Parameter "Output compressor stage 5030" not set correctly | Not stated | Yes |
| 17 | Compressor blocked | Yes | Yes |
| 18 | Compressor fault (general message) | Partly | Yes |
| 20 | Condensing pressure too high (control high pressure) | Yes | Yes |
| 21 | Inadequate evaporation pressure (low pressure fault) | Yes | Yes |
| 22 | Excessively high hot gas temperature | Yes | Yes |
| 23 | Flow sensor sec. 2: Operation with temperature value of return temperature sensor in secondary circuit of heat pump stage 2, plus 5 K.; If the secondary circuit flow and return … | Yes | Yes |
| 24 | Compressor failed to start: Message "88" has occurred 3 times successively. | Yes | Yes |
| 25 | Operating point is outside the application limits. | Yes | Yes |
| 26 | Max. defrost time exceeded | Not stated | Yes |
| 27 | Compression ratio too high | Yes | Yes |
| 28 | Max. high pressure | Yes | Yes |
| 29 | Condensing temperature too high | Yes | Yes |
| 30 | Operating point outside the compressor application limits for longer than max. time | Yes | Yes |
| 31 | Max. differential between evaporation and condensation temperature reached | Yes | Yes |
| 32 | Evaporator temp.sensr: No central heating or central cooling; only defrosting; The air discharge temperature sensor is used for defrosting the evaporator. | Partly | Yes |
| 33 | Central heating/DHW heating: Secondary circuit flow temperature too low | No | Yes |
| 34 | Evaporation temperature too low | Yes | Yes |
| 35 | Minimum suction gas temperature undershot | Varies by model | Yes |
| 36 | Min. pressure differential between high and low pressure side exceeded before compressor start | Yes | Yes |
| 37 | Hot gas temp sensor 2: Compressor 2 in a 2-stage refrigerant circuit is switched OFF. | Yes | Yes |
| 38 | Flow sensor primary: Operation with temperature value of return temperature sensor in primary circuit, plus 3 K.; If the primary circuit flow and return temperature sensors are both faulty at … | Yes | Yes |
| 39 | Difference between flow temperature in the appliance and return temperature is larger than 12 K prior to defrosting. | Yes | Yes |
| 40 | Flow sensor HC2: Heating circuit mixer M2/HC2 is closed. | Not stated | Yes |
| 41 | Flow sensor HC3: Mixer heating circuit M3/HC3 is closed. | Not stated | Yes |
| 43 | Short circuit/lead break, temperature sensor, refrigerant circuit controller | Varies by model | Yes |
| 44 | Short circuit/lead break, secondary circuit flow temperature sensor (upstream of instantaneous heating water heater) | Varies by model | Yes |
| 45 | Coolant buff fl t sens: No cooling operation with coolant buffer cylinder. | Partly | Yes |
| 46 | Short circuit/lead break, liquid gas temperature sensor | Yes | Yes |
| 47 | Short circuit/lead break, reversible suction gas temperature sensor | Yes | Yes |
| 48 | Suction gas superheating too low | Yes | Yes |
| 49 | Evaporator max. operating pressure (MOP) has been reached; changeover from superheating to pressure control of the suction gas. | No | Yes |
| 50 | Cylinder sensor top: If only the upper cylinder temperature sensor is present: No DHW heating; If an additional lower temperature sensor is installed: DHW heating possible, switched on and off … | Partly | Yes |
| 52 | Cylinder sensor bottom: If only the lower cylinder temperature sensor is present: No DHW heating; If an additional upper temperature sensor is installed: DHW heating possible, switched on and off … | Partly | Yes |
| 54 | Min. flow temperature primary circuit (brine inlet) not achieved. | Yes | Yes |
| 55 | Too little refrigerant | Yes | Yes |
| 56 | Condenser frost risk | Yes | Yes |
| 57 | Electronic expansion valve for refrigerant collector level control fully open | Yes | Yes |
| 58 | Liquid gas supercooling too high | Varies by model | Yes |
| 59 | Electronic expansion valve faulty | Yes | Yes |
| 60 | DHW heating via auxiliary heat exchanger fault | Not stated | Yes |
| 61 | Fan fault | Varies by model | Yes |
| 62 | Flow switch does not detect a flow rate. | Not stated | Yes |
| 63 | Lower outside temperature limit not reached | Not stated | Yes |
| 65 | Charge level sensor of refrigerant collector faulty | Varies by model | Yes |
| 66 | Motor overload relay or safety equipment at the soft starter has responded. | Varies by model | Yes |
| 67 | Flow switch has responded. | Not stated | Yes |
| 68 | Communication between controller PCB and EEV PCB is faulty | Not stated | Yes |
| 69 | Calculation error, refrigerant circuit | Varies by model | Yes |
| 70 | Short circuit/lead break, secondary circuit flow temperature sensor downstream of instantaneous heating water heater | Yes | Yes |
| 71 | Short circuit/lead break, secondary circuit return temperature sensor | Yes | Yes |
| 72 | Room temp. sensor HC3: No frost protection mode via room temperature sensor; No room temperature hook-up; No room temperature-dependent control | Not stated | Yes |
| 73 | Room temp. sensor SKK: No cooling mode | Partly | Yes |
| 78 | Room temp. sensor HC1: No frost protection mode via room temperature sensor; No room temperature hook-up; No room temperature-dependent control | Not stated | Yes |
| 79 | Room temp. sensor HC2: No frost protection mode via room temperature sensor; No room temperature hook-up; No room temperature-dependent control | Not stated | Yes |
| 80 | Max. compressor current exceeded | Yes | Yes |
| 81 | Max. compressor output exceeded | Yes | Yes |
| 82 | Mains voltage too high | Yes | Yes |
| 83 | Mains voltage too low | Yes | Yes |
| 84 | Temperature at the inverter too high | Yes | Yes |
| 85 | Temperature at inverter too low due to low outside temperature | Yes | Yes |
| 86 | Inverter power consumption too high | Yes | Yes |
| 87 | Temperature at compressor motor too high | Yes | Yes |
| 88 | Compressor drive fault | Yes | Yes |
| 89 | Internal inverter fault | Yes | Yes |
| 90 | Compressor control fault | Yes | Yes |
| 91 | Fan fault at inverter heat sink | Yes | Yes |
| 92 | Compressor does not reach its set speed. | Varies by model | Yes |
| 93 | Compressor drive fault | Varies by model | Yes |
| 94 | Inverter communication fault | Yes | Yes |
| 95 | Discharge current at IGBT too high | Yes | Yes |
| 96 | Precharge relay open | Varies by model | Yes |
| 97 | Voltage difference of individual phases too high (> 50 %) | Varies by model | Yes |
| 98 | Voltage difference of individual phases too high (> 5 A) | Yes | Yes |
| 99 | Current difference of the individual phases on the compressor too high | Yes | Yes |
| A.2 | Frost protection limit undershot | Not stated | Yes |
| A.11 | System pressure too low | Partly | Yes |
| A.12 | Real time clock battery flat | Not stated | Yes |
| A.16 | Insufficient flow rate | Yes | Yes |
| A.17 | Temperature for hygiene function not reached | Not stated | Yes |
| A.21 | System pressure has exceeded maximum pressure | Not stated | Yes |
| A.61 | Reduced heating output, electric booster heater | Partly | Yes |
| A.62 | Lead break, feedback signal, circulation pump heating circuit 1 | Not stated | Yes |
| A.63 | Lead break, feedback signal, heating circuit pump, heating/cooling circuit 2 | Not stated | Yes |
| A.65 | Dry run, heating circuit pump for heating/cooling circuit 2 | Partly | Yes |
| A.66 | Fault, feedback signal, secondary pump/heating circuit pump for heating/cooling circuit 1 | Partly | Yes |
| A.68 | Fault, feedback signal, heating circuit pump, heating/cooling circuit 2 | Not stated | Yes |
| A.69 | Incorrect manufacturer identification, heating circuit pump for heating/cooling circuit 2 | Partly | Yes |
| A.70 | Filter in ball valve of outdoor unit is contaminated | Not stated | Yes |
| A.71 | Excess current, compressor | Partly | Yes |
| A.72 | Current, power factor correction filter | Not stated | Yes |
| A.73 | Frequency deviation, compressor speed | Partly | Yes |
| A.74 | Pressure drop in secondary circuit | Not stated | Yes |
| A.75 | Pressure spikes in secondary circuit | Not stated | Yes |
| A.80 | Fan blocked | Yes | Yes |
| A.81 | Air/refrigerant heat exchanger restricted | Yes | Yes |
| A.82 | Fault, pressure sensor, CAN bus subscriber | Not stated | Yes |
| A.83 | Cylinder temperature sensor signal not plausible | Partly | Yes |
| A.84 | Signal not plausible, return temperature sensor in secondary circuit | Partly | Yes |
| A.85 | Sensor signal for outlet temperature not plausible | Partly | Yes |
| A.86 | Signal not plausible, flow temperature sensor in heating/cooling circuit 1 | Partly | Yes |
| A.87 | Signal not plausible, flow temperature sensor in heating/cooling circuit 2 | Partly | Yes |
| A.88 | Evaporator overheating | Partly | Yes |
| A.89 | Condenser overheating | Partly | Yes |
| A.90 | Temperature, hot gas temperature sensor CTT | Partly | Yes |
| A.91 | Comfort guarantee mode active | Not stated | Yes |
| A.93 | Hot gas pressure not plausible | Partly | Yes |
| A.94 | Suction gas pressure not plausible | Partly | Yes |
| A.96 | Air in the secondary circuit | Not stated | Yes |
| A.99 | Secondary circuit flow temperature too low | Partly | Yes |
| A.100 | EEPROM reset to factory settings | Not stated | Yes |
| A.101 | Hot gas temperature sensor signal not plausible | Partly | Yes |
| A.102 | Suction gas temperature sensor signal not plausible | Partly | Yes |
| A.104 | The lag appliance shows a warning | Partly | Yes |
| A.109 | Target temperature not reached | Partly | Yes |
| A.110 | Maximum temperature reached, external heat/cooling generator 1 | Partly | Yes |
| A.111 | Maximum temperature reached, external heat/cooling generator 2 | Partly | Yes |
| A.112 | Unstable DC voltage in inverter intermediate circuit | Partly | Yes |
| A.113 | Unstable DC voltage in inverter intermediate circuit | Partly | Yes |
| A.115 | Unstable mains voltage (power supply utility) | Partly | Yes |
| A.116 | Unstable mains voltage (power supply utility) | Partly | Yes |
| A.117 | Unstable frequency, mains voltage (power supply utility) | Partly | Yes |
| A.119 | Outdoor unit output exceeded | Partly | Yes |
| A.120 | Compressor not started after demand | Partly | Yes |
| A.121 | Inverter overheated | Partly | Yes |
| A.122 | Minimum evaporation temperature reached | Partly | Yes |
| A.125 | Heating mode: Evaporator overheating | Partly | Yes |
| A.137 | Unexpected compressor shutdown | Partly | Yes |
| A.138 | Compressor does not start | Partly | Yes |
| A.143 | Defrost process cancelled | Partly | Yes |
| A.152 | Wallbox overload protection not active | Partly | Yes |
| A.153 | No PV-optimised charging | Partly | Yes |
| A.159 | Factory setting, inverter | Partly | Yes |
| A.162 | Inverter overvoltage, intermediate circuit | Partly | Yes |
| A.163 | Inverter overvoltage, intermediate circuit (software) | Partly | Yes |
| A.164 | Increased voltage fluctuation, intermediate circuit, inverter | Partly | Yes |
| A.172 | Room frost protection function active | Partly | Yes |
| A.174 | Faulty fan of inverter in outdoor unit | Partly | Yes |
| A0 | Current sensor phase L1 of compressor supply voltage faulty | Yes | Yes |
| A1 | Current sensor phase L2 of compressor supply voltage faulty | Yes | Yes |
| A2 | Current sensor phase L3 of compressor supply voltage faulty | Yes | Yes |
| A3 | Current sensor power factor correction filter faulty | Yes | Yes |
| A4 | Temperature sensor, inverter (IGBT module) faulty | Varies by model | Yes |
| A5 | Temperature sensor power factor correction filter faulty | Yes | Yes |
| A6 | Secondary pump: No flow rate in the secondary circuit: Secondary pump is not running.; The change in the secondary circuit flow temperature for central heating/cooling is insufficient. | Not stated | Yes |
| A7 | Solar circuit pump: Inadequate change of temperature in the DHW cylinder | Not stated | Yes |
| A8 | Compressor drive overheated | Yes | Yes |
| A9 | Current phase L1 of compressor too high | Yes | Yes |
| AA | Current phase L2 of compressor too high | Yes | Yes |
| AB | Current phase L3 of compressor too high | Yes | Yes |
| AC | Current of power factor correction filter too high (detected via sensor) | Yes | Yes |
| AD | Current of power factor correction filter too high (detected via software) | Yes | Yes |
| AE | Voltage of power factor correction filter too high | Yes | Yes |
| AF | Cylinder primary pump: Inadequate change of temperature in the DHW cylinder | Not stated | Yes |
| B0 | Fan communication fault | Varies by model | Yes |
| B1 | Fan motor overheats | Varies by model | Yes |
| B2 | Fan motor speed monitor faulty | Varies by model | Yes |
| B3 | Motor of fan 1 (top) blocked | No | Yes |
| B4 | Fan motor supply voltage too low | No | Yes |
| B5 | Motor of fan 2 (bottom) blocked | No | Yes |
| B7 | KM BUS external unit: Compressor external unit does not; Energy statement not calculated corstart. rectly (see chapter "Diagnosis energy statement"). (cont.) | Not stated | Yes |
| B9 | Secondary pump blocked | Yes | Yes |
| BA | Secondary pump electrical fault | Yes | Yes |
| BB | Fault, PWM signal from secondary pump (actual speed) | Varies by model | Yes |
| BC | Secondary pump run dry | Yes | Yes |
| BD | KM BUS remt. ctrl HC2: No room temperature-dependent con-; No room temperature hook-up for trol for heating circuit with mixer M2. heating circuit with mixer M2. | Not stated | Yes |
| BE | KM BUS remt. ctrl HC3: No room temperature-dependent con-; No room temperature hook-up for trol for heating circuit with mixer M3. heating circuit with mixer M3. | Not stated | Yes |
| BF | Communication module: No communication via LON. | Not stated | Yes |
| C2 | Power supply: Compressor stops. | Yes | Yes |
| C3 | Pressure switch prim.: Compressor stops. | Yes | Yes |
| C4 | Slip of compressor drive too high | Yes | Yes |
| C5 | Power-OFF: Compressor stops. | Yes | Yes |
| C9 | Refrigerant circ (SHD): Compressor is switched off.; Central heating and DHW heating occurs with other heat sources enabled for this purpose, e.g. an external heat generator or instantaneous heating water … | Yes | Yes |
| CA | Protectn device primry: Compressor stops. | Yes | Yes |
| CB | Flow temp. primary: Compressor stops. | Yes | Yes |
| CC | Coding card: Heat pump does not start. | Not stated | Yes |
| CD | KM BUS Vitocom: No communication via Vitocom 100. | Not stated | Yes |
| CE | KM BUS extension: Functions for components connected to Example: external extension H1 are not available.; No swimming pool heating.; No switching of lag heat pumps in a cascade.; No external … | Not stated | Yes |
| CF | Communication module: No communication via LON. | Not stated | Yes |
| D1 | Compressor safety: Compressor stops. | Yes | Yes |
| D3 | Low pressure: Compressor stops. | Yes | Yes |
| D4 | Control high pressure: Compressor stops. | Yes | Yes |
| D5 | Contact humidistat: Compressor stops. | Yes | Yes |
| D6 | Flow switch: Compressor stops. | Yes | Yes |
| D7 | Flow switch: Heat pump does not start. | Not stated | Yes |
| DA | Compressor 2, safety: Compressor heat pump stage 2 stops. | Not stated | Yes |
| DB | Refrig. circ (SHD) 2: Compressor heat pump stage 2 stops. | Not stated | Yes |
| DC | Low pressure 2: Compressor heat pump stage 2 stops. | Not stated | Yes |
| DD | Ctrl high pressure 2: Compressor heat pump stage 2 stops. | Not stated | Yes |
| DE | Prot.primry pump/fan2: Compressor heat pump stage 2 stops. | Not stated | Yes |
| DF | Flow switch: Heat pump does not start. | Not stated | Yes |
| E000 | Remote off (blocks: Machine) | Yes | Yes |
| E0 | LON subscriber: No communication with the subscriber via LON | Not stated | Yes |
| E001 | High pressure alarm (blocks: Machine) | Yes | Yes |
| E1 | External heat source: Heat pump control unit cannot start external heat source. | Not stated | Yes |
| E002 | Low pressure alarm (blocks: Machine) | Yes | Yes |
| E2 | Lag heat pump: Heat pump control unit cannot start lag heat pump. | Not stated | Yes |
| E005 | Antifreeze alarm (blocks: Machine) | Yes | Yes |
| E006 | Flow alarm (blocks: Machine) | Yes | Yes |
| E6 | Fault at LON subscbr.: No communication via LON with the subscriber, e.g. a lag heat pump of a heat pump cascade | Not stated | Yes |
| E008 | Compressor driver limitation alarm (blocks: Machine) | Yes | Yes |
| E8 | Heat management: Electricity prices not set: "Economical" control strat-; If both are missing: Dual mode operation with fixed egy is not available. limits; Primary energy factors not set: "Ecological" control … | Not stated | Yes |
| E009 | Discharge high temperature alarm (blocks: Machine) | Yes | Yes |
| E010 | Solar collector high temperature alarm (blocks: Solar pump) | Partly | Yes |
| E018 | Cooling high temperature alarm (blocks: Machine) | Yes | Yes |
| E020 | Inverted trasductors pressure alarm (blocks: Machine/san) | Yes | Yes |
| E041 | Inconsistent temperatures alarm (blocks: Machine) | Yes | Yes |
| E042 | Insufficient thermal exchange alarm (blocks: Machine/DHW) | Yes | Yes |
| E050 | DHW storage tank high temperature alarm | Partly | Yes |
| E101 | Communication timeout with Slave 1 (blocks: Machine) | Yes | Yes |
| E611 | Water inlet probe failure (blocks: Machine) | Yes | Yes |
| E621 | Water outlet probe failure (blocks: Machine) | Yes | Yes |
| E631 | Compressor intake probe failure (blocks: Machine) | Yes | Yes |
| E641 | Compressor discharge probe fault / high pressure switch trip (blocks: Machine) | Yes | Yes |
| E651 | Outdoor air probe failure (blocks: Machine) | Yes | Yes |
| E661 | DHW probe failure (blocks: Machine) | Yes | Yes |
| E671 | Plant remote probe failure (blocks: Machine) | Yes | Yes |
| E691 | Low pressure transducer failure (blocks: Machine) | Yes | Yes |
| E701 | High pressure probe failure (blocks: Machine) | Yes | Yes |
| E711 | 0-10Vdc live input failure (blocks: Machine) | Yes | Yes |
| E801 | Pressure inverter timeout (blocks: Compressor) | Yes | Yes |
| E851 | Inverter Hardware problem (blocks: Compressor) | Yes | Yes |
| E861 | Motor current too high (blocks: Compressor) | Yes | Yes |
| E871 | Heatsink over-heat protection (blocks: Compressor) | Yes | Yes |
| E881 | Supply voltage out of limits (DC Bus Error) (blocks: Compressor) | Yes | Yes |
| E891 | Driver protection-output phase loss (blocks: Compressor) | Yes | Yes |
| E901 | Compressor driver and model mismatch (blocks: Compressor) | Yes | Yes |
| E911 | Overload protection (blocks: Compressor) | Yes | Yes |
| E921 | PFC POE over current (blocks: Compressor) | Yes | Yes |
| E931 | Comunication error with main controller (blocks: Compressor) | Yes | Yes |
| E941 | PFC converter fault (blocks: Compressor) | Yes | Yes |
| E951 | Heatsink and/or ambient temperature sensor error (blocks: Compressor) | Yes | Yes |
| E961 | Abnormal condition (blocks: Compressor) | Yes | Yes |
| E971 | EEPROM not initialize (blocks: Compressor) | Yes | Yes |
| ED | Ventilation comm.: Ventilation unit is switched off. Note After the time "Delay, subs. failure ventilation 7D90", message "EF Modbus subscriber" appears automatically. | Yes | Yes |
| EE | KM BUS subscriber | Not stated | Yes |
| EF | Modbus subscriber | Not stated | Yes |
| F.1 | Lead break, flow temperature sensor, secondary circuit | Yes | Yes |
| F.2 | Short circuit, flow temperature sensor, secondary circuit | Yes | Yes |
| F.3 | Lead break, return temperature sensor | Partly | Yes |
| F.4 | Short circuit, return temperature sensor | Partly | Yes |
| F.7 | Lead break, cylinder temperature sensor | Partly | Yes |
| F.8 | Short circuit, cylinder temperature sensor | Partly | Yes |
| F.13 | Lead break, outside temperature sensor | Partly | Yes |
| F.14 | Short circuit, outside temperature sensor | Partly | Yes |
| F.23 | Lead break, centre cylinder temperature sensor (DHW 2) | Partly | Yes |
| F.24 | Short circuit, centre cylinder temperature sensor (DHW 2) | Partly | Yes |
| F.27 | Lead break, top buffer temperature sensor | Partly | Yes |
| F.28 | Short circuit, top buffer temperature sensor | Partly | Yes |
| F.33 | Lead break, primary inlet temperature sensor, heat pump | Yes | Yes |
| F.34 | Short circuit, primary inlet temperature sensor, heat pump | Yes | Yes |
| F.74 | System pressure too low | Yes | Yes |
| F.75 | No flow rate in the secondary circuit | Yes | Yes |
| F.78 | No communication with the HMI programming unit | Not stated | Yes |
| F.87 | System overpressure | Not stated | Yes |
| F.91 | Communication error, DIO | Partly | Yes |
| F.92 | Communication error, ADIO | Partly | Yes |
| F.93 | M2IO electronics module communication error | Partly | Yes |
| F.94 | SDIO electronics module communication error | Partly | Yes |
| F.99 | Communication error PlusBus | Not stated | Yes |
| F.100 | PlusBus voltage error | Partly | Yes |
| F.101 | Short circuit, PlusBus | Partly | Yes |
| F.102 | Communication error, WiFi module | Not stated | Yes |
| F.103 | HMI programming unit communication error | Not stated | Yes |
| F.104 | External fault message input active | Not stated | Yes |
| F.111 | Lead break, liquid gas temperature sensor, heating | Yes | Yes |
| F.112 | Short circuit, liquid gas temperature sensor, heating | Yes | Yes |
| F.117 | Lead break, suction gas temperature sensor, evaporator | Yes | Yes |
| F.118 | Short circuit, suction gas temperature sensor, evaporator | Yes | Yes |
| F.121 | Communication error, inverter | Yes | Yes |
| F.123 | Lead break, liquid gas temperature sensor, condenser | Yes | Yes |
| F.124 | Short circuit, liquid gas temperature sensor, condenser | Yes | Yes |
| F.134 | Communication error, inverter | Not stated | Yes |
| F.147 | Lead break, suction gas temperature sensor, compressor | Yes | Yes |
| F.148 | Short circuit, suction gas temperature sensor, compressor | Yes | Yes |
| F.149 | Lead break, liquid gas temperature sensor, cooling | Not stated | Yes |
| F.150 | Short circuit, liquid gas temperature sensor, cooling | Partly | Yes |
| F.151 | Lead break, hot gas temperature sensor | Yes | Yes |
| F.152 | Short circuit, hot gas sensor | Yes | Yes |
| F.155 | Fault, electronic expansion valve 1 | Not stated | Yes |
| F.156 | Fault, electronic expansion valve 2 | Not stated | Yes |
| F.160 | CAN bus general communication fault between the affected electronics modules | Not stated | Yes |
| F.425 | Time synchronisation failed | Not stated | Yes |
| F.430 | Communication error, gateway | Not stated | Yes |
| F.431 | Communication error, KNX | Not stated | Yes |
| F.454 | Incorrect software version | Not stated | Yes |
| F.472 | Communication with energy meter interrupted | Not stated | Yes |
| F.519 | Communication error, BACnet | Not stated | Yes |
| F.520 | Internal fault, gateway | No | Yes |
| F.542 | Lead break, flow temperature sensor, heating/cooling circuit 1 with mixer Or Wrong setting during commissioning | Not stated | Yes |
| F.543 | Short circuit, flow temperature sensor, heating/cooling circuit 1 with mixer | Not stated | Yes |
| F.544 | Lead break, flow temperature sensor, heating/cooling circuit 2 | Not stated | Yes |
| F.545 | Short circuit, flow temperature sensor, heating/cooling circuit 2 | Not stated | Yes |
| F.546 | Lead break, flow temperature sensor, heating/cooling circuit 3 | Not stated | Yes |
| F.547 | Short circuit, flow temperature sensor, heating/cooling circuit 3 | Not stated | Yes |
| F.548 | Lead break, flow temperature sensor, heating/cooling circuit 4 | Not stated | Yes |
| F.549 | Short circuit, flow temperature sensor, heating/cooling circuit 4 | Not stated | Yes |
| F.575 | Lead break, room temperature sensor, heating/cooling circuit 1 | No | Yes |
| F.576 | Short circuit, room temperature sensor, heating/cooling circuit 1 | No | Yes |
| F.578 | Lead break, room temperature sensor, heating/cooling circuit 2 | No | Yes |
| F.579 | Short circuit, room temperature sensor, heating/cooling circuit 2 | No | Yes |
| F.581 | Lead break, room temperature sensor, heating/cooling circuit 3 | No | Yes |
| F.582 | Short circuit, room temperature sensor, heating/cooling circuit 3 | No | Yes |
| F.584 | Lead break, room temperature sensor, heating/cooling circuit 4 | No | Yes |
| F.585 | Short circuit, room temperature sensor, heating/cooling circuit 4 | No | Yes |
| F.616 | Incompatible software version in controller group recognised | Not stated | Yes |
| F.623 | Lead break, return temperature sensor | Not stated | Yes |
| F.624 | Short circuit, return temperature sensor | Not stated | Yes |
| F.625 | Lead break, return temperature sensor, heating/ cooling circuit 2 | Not stated | Yes |
| F.626 | Short circuit, return temperature sensor, heating/ cooling circuit 2 | Not stated | Yes |
| F.627 | Lead break, return temperature sensor, heating/ cooling circuit 3 | Not stated | Yes |
| F.628 | Short circuit, return temperature sensor, heating/ cooling circuit 3 | Not stated | Yes |
| F.629 | Lead break, return temperature sensor, heating/ cooling circuit 4 | Not stated | Yes |
| F.630 | Short circuit, return temperature sensor, heating/ cooling circuit 4 | Not stated | Yes |
| F.685 | Communication error, HPMU electronics module | Partly | Yes |
| F.686 | Communication error, refrigerant circuit controller | Not stated | Yes |
| F.687 | Communication error, EHCU | Yes | Yes |
| F.744 | The programming unit is not compatible | Partly | Yes |
| F.745 | Incompatible system configuration | Not stated | Yes |
| F.747 | Internal fault, programming unit | Not stated | Yes |
| F.748 | Fault in touch panel of HMI programming unit | Partly | Yes |
| F.749 | Control unit firmware versions not compatible with each other | Not stated | Yes |
| F.764 | Another CAN bus subscriber reports a fault | Partly | Yes |
| F.765 | Communication error with another CAN bus subscriber | Partly | Yes |
| F.770 | Lead break, flow temperature sensor, secondary circuit downstream of condenser | Yes | Yes |
| F.771 | Short circuit, flow temperature sensor, secondary circuit downstream of condenser | Yes | Yes |
| F.772 | Lead break, compressor oil sump temperature sensor | Not stated | Yes |
| F.773 | Short circuit, compressor oil sump temperature sensor | Not stated | Yes |
| F.788 | Lead break, 4/3-way valve | Partly | Yes |
| F.790 | Mechanical fault, 4/3-way valve | Partly | Yes |
| F.791 | Failure, instantaneous heating water heater, phase 1 | Not stated | Yes |
| F.792 | Failure, instantaneous heating water heater, phase 2 | Not stated | Yes |
| F.793 | Failure, instantaneous heating water heater, phase 3 | Not stated | Yes |
| F.797 | Mechanical fault, circulation pump, heating/cooling circuit 1 | Partly | Yes |
| F.798 | Mechanical fault, circulation pump, heating/cooling circuit 2 | Partly | Yes |
| F.799 | Electrical fault, circulation pump, heating/cooling circuit 1 | Partly | Yes |
| F.800 | Electrical fault, circulation pump, heating/cooling circuit 2 | Partly | Yes |
| F.801 | Malfunction, refrigerant circuit reversal valve | Not stated | Yes |
| F.807 | Fan fault | Partly | Yes |
| F.808 | Fault, lower fan | Partly | Yes |
| F.812 | Fault, upper fan | Not stated | Yes |
| F.819 | Lead break, electronic expansion valve 1 | Not stated | Yes |
| F.820 | Lead break, electronic expansion valve 2 | Not stated | Yes |
| F.823 | Short circuit, electronic expansion valve 1 | Not stated | Yes |
| F.824 | Short circuit, electronic expansion valve 2 | Not stated | Yes |
| F.827 | High limit safety cut-out has responded. | Not stated | Yes |
| F.829 | Filter in ball valve of outdoor unit is contaminated | Not stated | Yes |
| F.830 | Fault, inverter current sensor | Yes | Yes |
| F.831 | Fault, current sensor, power factor correction filter (PFC) inverter | Yes | Yes |
| F.832 | Inverter temperature sensor (IPM) faulty | Yes | Yes |
| F.833 | Fault, temperature sensor, power factor correction filter (PFC) inverter | Yes | Yes |
| F.834 | Inverter phase fault on mains side | Yes | Yes |
| F.835 | Inverter parameter settings faulty | Yes | Yes |
| F.836 | Load current of inverter too high (excess current) | Yes | Yes |
| F.837 | Inverter electric phase connection to compressor faulty | Yes | Yes |
| F.838 | Inverter control faulty | Yes | Yes |
| F.839 | Compressor blocked | Yes | Yes |
| F.840 | Inverter phase currents to compressor asymmetrical | Partly | Yes |
| F.841 | Compressor torque too high | Not stated | Yes |
| F.842 | Short circuit, inverter internal power module | Partly | Yes |
| F.843 | Inverter overcurrent shutdown, power factor correction filter (PFC) | Yes | Yes |
| F.844 | Inverter, internal reference voltage fault | Yes | Yes |
| F.845 | Inverter parameter settings faulty | Yes | Yes |
| F.846 | Inverter, compressor rotating field counter-rotating | Yes | Yes |
| F.847 | Inverter current sensor recognises unchanging compressor current | Yes | Yes |
| F.848 | Inverter current sensor recognises fluctuating compressor current | Yes | Yes |
| F.864 | Defrost not completed successfully | Partly | Yes |
| F.865 | Refrigerant circuit high pressure shutdown | Yes | Yes |
| F.866 | Refrigerant circuit low pressure shutdown | Yes | Yes |
| F.867 | Float air vent valve in the outdoor unit has responded. Too much air in the secondary circuit during venting Quick-action air vent; valve may be faulty Or Refrigerant present in … | Yes | Yes |
| F.875 | Communication error with connected main appliance | Partly | Yes |
| F.876 | Lead break, combined sensor, flow rate/temperature | Yes | Yes |
| F.877 | Short circuit, evaporator temperature sensor OMT | Yes | Yes |
| F.878 | Lead break, evaporator temperature sensor OMT | Yes | Yes |
| F.881 | Safety shutdown, refrigerant circuit | Partly | Yes |
| F.909 | No information on Energy Management (EMS) | Partly | Yes |
| F.910 | Multiple main appliances recognised | Not stated | Yes |
| F.912 | Inverter temperature sensor fault | Yes | Yes |
| F.913 | Interior temperature too high | Yes | Yes |
| F.914 | Inverter temperature too high | Not stated | Yes |
| F.915 | Short circuit, temperature sensor, inverter cooling HST | Not stated | Yes |
| F.916 | Lead break, temperature sensor, inverter cooling HST | Not stated | Yes |
| F.923 | Data from energy meter 1 not available | Partly | Yes |
| F.924 | Data from energy meter 2 not available | Partly | Yes |
| F.925 | Data from energy meter 3 not available | Partly | Yes |
| F.926 | Data from energy meter 4 not available | Partly | Yes |
| F.927 | Data from energy meter 5 not available | Partly | Yes |
| F.928 | Data from energy meter 6 not available | Partly | Yes |
| F.929 | Data from energy meter 7 not available | Partly | Yes |
| F.930 | Data from energy meter 8 not available | Partly | Yes |
| F.931 | Data from energy meter 9 not available | Partly | Yes |
| F.932 | Data from energy meter 10 not available | Partly | Yes |
| F.933 | Data from energy meter 11 not available | Partly | Yes |
| F.934 | Data from energy meter 12 not available | Partly | Yes |
| F.935 | Data from energy meter 13 not available | Partly | Yes |
| F.936 | Data from energy meter 14 not available | Partly | Yes |
| F.937 | Data from energy meter 15 not available | Partly | Yes |
| F.938 | Data from inverter 1 not available | Partly | Yes |
| F.939 | Data from inverter 2 not available | Partly | Yes |
| F.940 | Data from inverter 3 not available | Partly | Yes |
| F.941 | Data from inverter 4 not available | Partly | Yes |
| F.942 | Data from inverter 5 not available | Partly | Yes |
| F.943 | Data from inverter 6 not available | Partly | Yes |
| F.944 | Data from consumer 1 not available | Partly | Yes |
| F.945 | Data from consumer 2 not available | Partly | Yes |
| F.946 | Data from consumer 3 not available | Partly | Yes |
| F.947 | Data from consumer 4 not available | Partly | Yes |
| F.948 | Data from consumer 5 not available | Partly | Yes |
| F.949 | Data from consumer 6 not available | Partly | Yes |
| F.950 | Data from consumer 7 not available | Partly | Yes |
| F.951 | Data from consumer 8 not available | Partly | Yes |
| F.952 | Data from consumer 9 not available | Partly | Yes |
| F.953 | Data from consumer 10 not available | Partly | Yes |
| F.954 | Data from consumer 11 not available | Partly | Yes |
| F.955 | Data from consumer 12 not available | Partly | Yes |
| F.956 | Data from consumer 13 not available | Partly | Yes |
| F.957 | Data from consumer 14 not available | Partly | Yes |
| F.958 | Data from consumer 15 not available | Partly | Yes |
| F.959 | Data from generator 1 not available | Partly | Yes |
| F.960 | Data from generator 2 not available | Partly | Yes |
| F.961 | Data from generator 3 not available | Partly | Yes |
| F.962 | Data from generator 4 not available | Partly | Yes |
| F.963 | Data from generator 5 not available | Partly | Yes |
| F.964 | Data from generator 6 not available | Partly | Yes |
| F.965 | Data from battery module 1 not available | Partly | Yes |
| F.966 | Data from battery module 2 not available | Partly | Yes |
| F.967 | Data from battery module 3 not available | Partly | Yes |
| F.968 | Data from battery module 4 not available | Partly | Yes |
| F.969 | Data from battery module 5 not available | Partly | Yes |
| F.970 | Data from battery module 6 not available | Partly | Yes |
| F.980 | Required flow rate for DHW heating not reached | Partly | Yes |
| F.981 | Minimum flow rate for DHW undershot | Partly | Yes |
| F.982 | Heating circuit pump running dry | Partly | Yes |
| F.983 | Inverter EEPROM faulty | Not stated | Yes |
| F.984 | Repeated control fault, electronic expansion valve 1 | Not stated | Yes |
| F.985 | Repeated control fault, electronic expansion valve 2 | Not stated | Yes |
| F.990 | Short circuit, low loss header temperature sensor | Not stated | Yes |
| F.991 | Lead break, low loss header temperature sensor | Not stated | Yes |
| F.992 | Short circuit, temperature sensor in heating/cooling water buffer cylinder | Partly | Yes |
| F.993 | Lead break, temperature sensor in heating/cooling water buffer cylinder | Partly | Yes |
| F.994 | Short circuit, temperature sensor in heating water buffer cylinder | Partly | Yes |
| F.995 | Lead break, temperature sensor in heating water buffer cylinder | Partly | Yes |
| F.996 | Short circuit, temperature sensor in cooling water buffer cylinder | Partly | Yes |
| F.997 | Lead break, temperature sensor in cooling water buffer cylinder | Partly | Yes |
| F.998 | Communication error, refrigerant circuit controller to EHCU/flow rate signal | Partly | Yes |
| F.999 | Communication error, HIO | Not stated | Yes |
| F.1006 | Heat pump start count exceeded | Not stated | Yes |
| F.1007 | Heat pump locked | Not stated | Yes |
| F.1008 | Number of supported devices on main control unit exceeded | Not stated | Yes |
| F.1009 | Fault, heat pump electric compressor heating | Yes | Yes |
| F.1010 | Water pressure sensor fault | Yes | Yes |
| F.1011 | Fault, high pressure sensor, refrigerant circuit | Yes | Yes |
| F.1012 | Fault, low pressure sensor, refrigerant circuit | Yes | Yes |
| F.1013 | Incorrect setting of the DIP switches | Yes | Yes |
| F.1014 | Incorrect setting of the DIP switches | Not stated | Yes |
| F.1015 | Incorrect setting of the DIP switches | Not stated | Yes |
| F.1016 | Return temperature sensor in secondary circuit not recognised | Yes | Yes |
| F.1017 | Secondary circuit flow temperature sensor downstream of condenser not recognised | Yes | Yes |
| F.1018 | High pressure sensor ICT not recognised | Yes | Yes |
| F.1019 | Secondary heat exchanger, liquid gas temperature sensor not available | Yes | Yes |
| F.1022 | Fault, energy meter | Not stated | Yes |
| F.1034 | Communication fault, external CAN bus | No | Yes |
| F.1035 | Communication fault, internal CAN bus | No | Yes |
| F.1045 | Fault, external heat/cooling generator 1 | Not stated | Yes |
| F.1049 | Fault, 3/2-way mixing valve for dual mode operation | Not stated | Yes |
| F.1050 | Short circuit, temperature sensor, external heat/cooling generator 1 | Not stated | Yes |
| F.1051 | Lead break, temperature sensor, external heat/cooling generator 1 | Not stated | Yes |
| F.1054 | Maximum temperature, external heat/cooling generator 1 exceeded | Not stated | Yes |
| F.1056 | Faulty relay, inverter intermediate circuit | Yes | Yes |
| F.1057 | Fault, high pressure sensor, refrigerant circuit | Yes | Yes |
| F.1062 | Inverter voltage too low | Not stated | Yes |
| F.1063 | Voltage at inverter too high | Not stated | Yes |
| F.1065 | Power supply, power supply utility too low | Not stated | Yes |
| F.1066 | Power supply, power supply utility too high | Not stated | Yes |
| F.1067 | Frequency of the power supply, power supply utility too high | Not stated | Yes |
| F.1069 | Condenser overheating | Yes | Yes |
| F.1074 | Pressure differential too low for circuit reversal | Not stated | Yes |
| F.1076 | Compressor start count exceeded with oil temperature too low | Not stated | Yes |
| F.1077 | Minimum runtime of compressor repeatedly undershot | Not stated | Yes |
| F.1078 | Flow rate repeatedly too low at compressor startup | Not stated | Yes |
| F.1079 | Flow rate repeatedly too low during defrost process | Not stated | Yes |
| F.1080 | Evaporator temperature too low | Yes | Yes |
| F.1081 | Flow temperature of secondary circuit or heating/cooling circuit 1 too low | Yes | Yes |
| F.1082 | Condensing temperature during defrosting | Yes | Yes |
| F.1083 | Evaporator temperature in cooling mode too high | Yes | Yes |
| F.1085 | Mechanical fault, cylinder loading pump | Partly | Yes |
| F.1086 | Electrical fault, cylinder loading pump | Partly | Yes |
| F.1087 | Cylinder loading pump running dry | Partly | Yes |
| F.1088 | Short circuit, return temperature sensor, cylinder loading system | Partly | Yes |
| F.1089 | Lead break, return temperature sensor, cylinder loading system | Partly | Yes |
| F.1090 | Short circuit, flow temperature sensor, cylinder loading system | Partly | Yes |
| F.1091 | Lead break, flow temperature sensor, cylinder loading system | Partly | Yes |
| F.1092 | Incorrect configuration of refrigerant circuit controller | Yes | Yes |
| F.1093 | Fault, electronics module, cylinder loading pump | Partly | Yes |
| F.1094 | No flow rate in the cylinder loading system | Partly | Yes |
| F.1105 | Cooling function for heating/cooling circuit 1 is not supported by extension module | Not stated | Yes |
| F.1106 | Cooling function for heating/cooling circuit 2 is not supported by extension module | Not stated | Yes |
| F.1107 | Cooling function for heating/cooling circuit 3 is not supported by extension module | Not stated | Yes |
| F.1108 | Cooling function for heating/cooling circuit 4 is not supported by extension module | Not stated | Yes |
| F.1129 | Fault on inverter | Not stated | Yes |
| F.1130 | No connection to the datalogger | Partly | Yes |
| F.1131 | Network fault (LAN) | Partly | Yes |
| F.1132 | Peak output for inverter incorrectly configured | Not stated | Yes |
| F.1172 | Inverter recognises asymmetrical compressor currents | Partly | Yes |
| F.1173 | Maximum number of inverter safety shutdowns interlock input 1 reached | Yes | Yes |
| F.1174 | Forced safety shutdown, compressor - interlock input 2 active | Partly | Yes |
| F.1175 | Maximum number of inverter safety shutdowns interlock input 2 reached | Partly | Yes |
| F.1179 | Internal safety shutdown, inverter, due to mains side phase fault | Partly | Yes |
| F.1180 | Inverter, safety-relevant internal earth fault | Partly | Yes |
| F.1181 | Safety shutdown, compressor, due to superimposed direct current | Partly | Yes |
| F.1182 | Safety shutdown, thermal overload protection, compressor | Partly | Yes |
| F.1183 | Fault, compressor start-up | Partly | Yes |
| F.1184 | Fault, mains voltage measurement, inverter | Partly | Yes |
| F.1186 | Offset error, inverter current sensor | Partly | Yes |
| F.1187 | Fault, inverter current sensor outside the valid range | Partly | Yes |
| F.1191 | Fault, sensor interlock input 1 | Partly | Yes |
| F.1192 | Fault, sensor interlock input 2 | Yes | Yes |
| F.1194 | Inverter overcurrent, internal power module | Partly | Yes |
| F.1195 | Fault, overload, inverter | Partly | Yes |
| F.1196 | Fault, analogue/digital converter, inverter | Not stated | Yes |
| F.1211 | CAN bus communication fault between indoor and outdoor unit | Not stated | Yes |
| F.1213 | Communication error, refrigerant circuit controller, outdoor unit 2 | Not stated | Yes |
| F.1216 | Loss of communication with the lead heat pump | Partly | Yes |
| F.1217 | Communication loss to the lag heat pump | Partly | Yes |
| F.1218 | Communication error with the slave heat pump | Partly | Yes |
| F.1221 | Excessive consumption of photovoltaic energy | Partly | Yes |
| F.1225 | Required oil sump temperature not reached | Yes | Yes |
| F.1233 | Electrical fault, electronic expansion valve 1 | Not stated | Yes |
| F.1234 | Electrical fault, electronic expansion valve 2 | Not stated | Yes |
| F.1254 | Safety shutdown, thermal overload protection after multiple compressor starts | Yes | Yes |
| F.1259 | Modbus communication fault, refrigerant circuit controller (VCMU) to inverter | Yes | Yes |
| F.1313 | No feedback, actual compressor speed | Yes | Yes |
| F.1317 | Short circuit, inverter temperature sensor | Yes | Yes |
| F.1318 | Lead break, inverter temperature sensor | Yes | Yes |
| F.1319 | Inverter temperature sensor fault | Yes | Yes |
| F.1320 | Communication error between HPMU and EHCU | No | Yes |
| F.1324 | Function check: Fault, instantaneous heating water heater | Not stated | Yes |
| F.1336 | Low pressure in refrigerant circuit | No | Yes |
| F.1337 | Lead break, feedback signal, heating circuit pump, heating/cooling circuit 2 | Partly | Yes |
| F.1341 | Lead break, dual mode temperature sensor | No | Yes |
| F.1343 | Short circuit, dual mode temperature sensor | No | Yes |
| F0 | Comprssr, refrig. circ: Compressor stops. | Yes | Yes |
| F1 | Comprssr2, refrig. circ: Compressor heat pump stage 2 stops. | Not stated | Yes |
| F2 | Parameters 5030/5130: Energy statement not calculated correctly. | Not stated | Yes |
| FE | Minimum room area: Heat pump with flammable refrigerant does not operate. | Not stated | Yes |
| FF | New start: Information display, no restriction of functions: Indicates that the heat pump has been re-started. | No | Yes |
| I.9 | Screed drying active | Not stated | Yes |
| I.10 | DHW heating runtime limit | Not stated | Yes |
| I.56 | External heat demand active | Not stated | Yes |
| I.57 | External blocking active | Not stated | Yes |
| I.63 | Cooling circuit not ready | Not stated | Yes |
| I.70 | Mains overcurrent - Load current in inverter intermediate circuit too high (excess current); Compressor temporarily off | Partly | Yes |
| I.71 | Mains overvoltage - Inverter mains voltage too high; Compressor temporarily off | Partly | Yes |
| I.72 | Mains undervoltage - Inverter mains voltage too low; Compressor temporarily off | Partly | Yes |
| I.73 | Overvoltage, DC link, inverter | Partly | Yes |
| I.74 | Undervoltage, DC link, inverter | Partly | Yes |
| I.75 | Excess temperature, internal power module, inverter | Partly | Yes |
| I.76 | Overtemperature, PFC inverter | Partly | Yes |
| I.77 | Overcurrent warning, PFC inverter | Partly | Yes |
| I.78 | Inverter current derating due to excessive power demand | Not stated | Yes |
| I.79 | Inverter current derating due to excessive power demand from compressor | Not stated | Yes |
| I.80 | Inverter field weakening operation due to excessive power demand from compressor | Not stated | Yes |
| I.81 | Derating due to excessive temperature of internal power module of inverter | Not stated | Yes |
| I.82 | Inverter output reduction due to excess temperature, power factor correction filter (derat- | Not stated | Yes |
| I.83 | 4/3-way valve min. flow rate reached | Not stated | Yes |
| I.84 | 4/3-way valve min. return temperature reached | Not stated | Yes |
| I.85 | Controlled low pressure shutdown, refrigerant circuit | Not stated | Yes |
| I.86 | Controlled high pressure shutdown, refrigerant circuit | Not stated | Yes |
| I.89 | Time set forward | Not stated | Yes |
| I.90 | Time set back | Not stated | Yes |
| I.92 | Reset energy statement | Not stated | Yes |
| I.96 | Pre-configured appliance was recognised on the external CAN | Not stated | Yes |
| I.97 | List of connected appliances was deleted from the main appliance | Not stated | Yes |
| I.98 | New appliance was recognised on the external CAN | Not stated | Yes |
| I.99 | Hygiene function target temperature reached | Not stated | Yes |
| I.100 | Max. condensation pressure reached | Yes | Yes |
| I.101 | Min. heating operation evaporation pressure reached | Yes | Yes |
| I.102 | Min. cooling operation evaporation pressure reached | Yes | Yes |
| I.103 | Max. evaporation pressure reached | Yes | Yes |
| I.104 | Maximum hot gas temperature reached | Yes | Yes |
| I.105 | Max. runtime lower evaporation temperature reached | Yes | Yes |
| I.106 | Max. compressor pressure differential reached | Yes | Yes |
| I.107 | Max. condensation temperature reached | Yes | Yes |
| I.108 | Max. compressor torque reached | Yes | Yes |
| I.109 | Max. compressor evaporation temperature reached | Partly | Yes |
| I.110 | Min. compressor pressure condition reached | Yes | Yes |
| I.111 | Min. compressor evaporation temperature reached | Yes | Yes |
| I.113 | SmartGrid forced shutdown active | Not stated | Yes |
| I.114 | Standard mode active | No | Yes |
| I.115 | SmartGrid recommended switch-on active | Not stated | Yes |
| I.116 | SmartGrid forced switch-on active | Not stated | Yes |
| I.117 | Home Energy Management System active | Not stated | Yes |
| I.118 | Underfloor temperature limiter heating circuit 1 activated | Not stated | Yes |
| I.119 | Underfloor temperature limiter heating circuit 2 activated | Not stated | Yes |
| I.120 | Low-noise mode in refrigerant circuit activated | Not stated | Yes |
| I.121 | Cooling circuit 1, contact humidistat activated | Not stated | Yes |
| I.122 | Cooling circuit 2, contact humidistat activated | Not stated | Yes |
| I.123 | Refrigerant circuit, max. return temperature reached | Not stated | Yes |
| I.124 | Refrigerant circuit, min. return temperature reached | Not stated | Yes |
| I.125 | Refrigerant circuit, max. primary inlet temperature reached | Not stated | Yes |
| I.126 | Refrigerant circuit, min. primary inlet temperature reached | Not stated | Yes |
| I.127 | Max. pressure differential for compressor start reached | Not stated | Yes |
| I.128 | Min. oil sump temperature reached | Not stated | Yes |
| I.129 | Heat pump operating reversal, pressure differential too low | Not stated | Yes |
| I.130 | Heat pump start phase timed out | Not stated | Yes |
| I.131 | Min. evaporation temperature reached | Not stated | Yes |
| I.132 | Heat pump control unit restarting | Not stated | Yes |
| I.133 | Heat pump control unit communication unit restarting | Not stated | Yes |
| I.134 | Forced de-icing activated | Not stated | Yes |
| I.135 | Controlled defrost active | No | Yes |
| I.137 | Connected appliance reports information message | Not stated | Yes |
| I.142 | Compressor minimum runtime violation | Not stated | Yes |
| I.143 | Heat pump blocked by power supply utility | Not stated | Yes |
| I.144 | Mains side frequency deviations detected | Not stated | Yes |
| I.155 | Message that screed drying has been cancelled by the user | Not stated | Yes |
| I.168 | Configuration as cascade main appliance | Not stated | Yes |
| I.169 | Configuration as cascade auxiliary appliance | Not stated | Yes |
| I.170 | In the event of a fault, a lag heat pump temporarily takes over the task of the lead heat pump. | Not stated | Yes |
| I.171 | Inverter - Software update running.; Inverter off; No action required | Not stated | Yes |
| I.173 | Inverter - Output current too high; Reduced compressor speed; No action required | Partly | Yes |
| I.174 | Inverter - The inverter output is temporarily reduced.; Reduced compressor speed; No action required | Partly | Yes |
| I.175 | Compressor does not start | Partly | Yes |
| I.176 | Compressor runs with reduced output | Not stated | Yes |
| I.178 | Temporary internal CAN bus communication fault between the electronics modules | Not stated | Yes |
| I.179 | Temporary Modbus communication fault between inverter and refrigerant circuit controller | Not stated | Yes |
| I.183 | Electronic expansion valve 1 deviated from target position | Not stated | Yes |
| I.184 | Electronic expansion valve 2 deviated from target position | Not stated | Yes |
| P.1 | Service due after interval. | Not stated | Yes |
| P.4 | Top up heating water. | Not stated | Yes |
| P.8 | Service due after hours run. | Not stated | Yes |
| P.34 | Maintenance of hydraulic filter strainer necessary | Not stated | Yes |
| P.37 | Maintenance of gas condensing boiler | No | Yes |