Worcester Bosch · A major brand in the UK. 245 codes across 10 product families, each taken from the manufacturer’s manuals. Worcester Bosch technical support ↗
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245 codes
| Code | Meaning | Stops? | Homeowner check? |
|---|---|---|---|
| 5H | Relay test was activated | No | Yes |
| 1000 | System configuration not confirmed (Systemkonfiguration nicht bestätigt) | Partly | Yes |
| 1010 | No communication via EMS BUS connection | Partly | Yes |
| 1017 | Info: operating pressure too low (Betriebsdruck zu niedrig) | Partly | Yes |
| 1038 | Time/date invalid value | No | Yes |
| 3091 | Room temperature sensor defective | Partly | Yes |
| 4052 | Thermal disinfection unsuccessful (Thermische Desinfektion misslungen) | No | Yes |
| 5111 | Alarm: signal from temperature sensor TC3 on the condenser outside permitted range | Yes | Yes |
| 5143 | Alarm: flow and return swapped between indoor and outdoor unit | Yes | Yes |
| 5197 | Hybrid circulation pump fault (PH0). | Partly | Yes |
| 5198 | Hybrid circulation pump (PH0) blocked or defective. | Partly | Yes |
| 5199 | Dry running of the hybrid circulation pump (PH0). | Partly | Yes |
| 5203 | Alarm: outside temperature sensor T1 fault | Partly | Yes |
| 5206 | Alarm: Z1 flow temperature sensor T0 fault | Yes | Yes |
| 5239 | Alarm: no signal from DHW temperature sensor TW1; DHW heating blocked | Partly | Yes |
| 5378 | Info: outdoor unit defrost fault | Partly | Yes |
| 5480 | No circulation to heat pump. | Partly | Yes |
| 5481 | No CAN communication between hybrid manager and outdoor unit. | Partly | Yes |
| 5482 | Signal from ret. temp. sensor TH2 on hybr. man. outside curve. | Partly | Yes |
| 5483 | Signal from ret. temp. sensor TH1 on hybr. man. outside curve. | Partly | Yes |
| 5484 | Chosen hyd. conf. n. supp. f. det. sys. | Partly | Yes |
| 5485 | Circulation to heat pump too low (Zu geringer Umlauf zur Wärmepumpe) | Partly | Yes |
| 5486 | No LIN bus communication. | Partly | Yes |
| 5487 | Defective low loss header temperature sensor on the hybrid manager | Partly | Yes |
| 5488 | Defective outside temperature sensor on the hybrid manager | Partly | Yes |
| 5489 | No values entered for energy prices. | No | Yes |
| 5490 | Signal from return temperature sensor TH2 on hybrid manager is outside the curve, cable break, sensor defective. | Partly | Yes |
| 5522 | Alarm: installer PCB and heat pump/IO PCB do not match | Yes | Yes |
| 5594 | Alarm: Z1 air in system | Yes | Yes |
| 5691 | Non-compatible SW version in the outdoor unit. | Partly | Yes |
| 5692 | Incompatible SW version in the heat generator, or unsupported heat generator connected. | Partly | Yes |
| 5693 | Internal fault in the outdoor unit. | Partly | Yes |
| 6242 | Alarm: safety temperature limiter FE on electric booster heater has tripped | Partly | Yes |
| 6243 | Warning: high temperature difference between heat pump flow and return sensors (TC1-TC0) | No | Yes |
| 6248 | Alarm: underfloor heating temperature limiter has tripped | Partly | Yes |
| 6253 | Alarm: temperature too high in electric booster heater EE | Partly | Yes |
| A01-811 | DHW provision: thermal disinfection unsuccessful | No | Yes |
| A01-5378 | Outdoor unit defrost failure | Partly | Yes |
| A01-5522 | Wrong combination of indoor and outdoor units | Yes | Yes |
| A01-5800 | Outdoor unit controller restarted (Info) | No | Yes |
| A01-5801 | Outdoor unit CAN gateway restarted (Info) | No | Yes |
| A01-5802 | No power supply at compressor (Info) | No | Yes |
| A01-5804 | Current sensor fault (Info) | No | Yes |
| A01-5806 | IPM driver pin fault (Info) | No | Yes |
| A01-5808 | AC input zero cross error (Info) | No | Yes |
| A01-5810 | Compressor current sensor fault (Info) | No | Yes |
| A8 | No communication with EMS heat appliance / No communication with system controller (status B) | Partly | Yes |
| A11-1000 | System configuration not confirmed | Partly | Yes |
| A11-1010 | No communication via BUS interface EMS 2 | Partly | Yes |
| A11-1037 | Outside temperature sensor – heating standby mode active (A61 = heating circuit 1…A64 = heating circuit 4) | Partly | Yes |
| A11-1038 | Invalid time/date | No | Yes |
| A11-1094 | No communication with ventilation unit. | No | Yes |
| A11-3061 | No communication with mixer module (3061 = heating circuit 1...3064 = heating circuit 4) | Partly | Yes |
| A11-3091 | Room temperature sensor defective (3091 = heating circuit 1...3094 = heating circuit 4) | Partly | Yes |
| A11-3091-CR10H | Remote control not registered correctly in the system / Room temperature sensor for remote control is faulty (A11/3091: heating/cooling circuit 1 ... 3094: circuit 4) | Partly | Yes |
| A11-6004 | No communication with solar module | Partly | Yes |
| A21-1001 | CR 10 H in heating circuit 1 incorrectly configured | Partly | Yes |
| A21-3141 | Sensor for relative humidity in the remote control is faulty (A21/3141: heating/cooling circuit 1 ... A24/3144: circuit 4) | Partly | Yes |
| A22-1001 | BUS signal from the higher-level user interface for remote control is missing (A22: heating circuit 2 ... A28: heating circuit 8) | Partly | Yes |
| A31-3021 | Heating circuit 1…4 flow temperature sensor faulty – standby mode active (A31/3021 = heating circuit 1…A34/3024 = heating circuit 4) | Partly | Yes |
| A51-6021 | Solar collector temperature sensor defective | Partly | Yes |
| A51-6022 | Cylinder 1 Bottom temp. sensor faulty - heating standby mode active | Partly | Yes |
| A61-1010 | No communication via BUS connection EMS 2. | Partly | Yes |
| A61-1081 | Two master control units in the system (A61/1081 = heating circuit 1…A64/1084 = heating circuit 4) | Partly | Yes |
| A61-1081-CR10H | CR 10 H incorrectly configured (A61/1081: heating circuit 1 ... A68/1088: heating circuit 8) | Partly | Yes |
| A61-3061 | CR 10 H incorrectly configured (A61/3061: heating circuit 1 ... A68/3068: heating circuit 8) | Partly | Yes |
| A61-3091 | Room temperature sensor for CR 10 H is faulty (A61/3091: heating circuit 1 ... A68/3098: heating circuit 8) | Partly | Yes |
| Add-heat-is-now-working-at-its-highest-permitted-temperature | Info window: Add. heat is now working at its highest permitted temperature | Partly | Yes |
| Additional-heat-is-now-working-at-its-highest-temperature | Additional heat is now working at its highest temperature | No | Yes |
| Air-Water-pump-not-connected | Alarm window: Air/Water pump not connected | Yes | Yes |
| Alarm-heat-pump | Alarm: Alarm heat pump | Yes | Yes |
| bH | Alarm table: PED board failure / Troubleshooting table: PED board error | Yes | Yes |
| C0 | Alarm table: Multiple units configured as Master in the M/S network. / Troubleshooting table: multiple units configured as master in the master - slave network (printed 'CO') | Partly | Yes |
| C7 | Alarm table: Heat sink over-temperature protection | Yes | Yes |
| CC | Outside temperature sensor faulty (status B) | Partly | Yes |
| Check-CANbus-cable-connection | Check CANbus cable connection | Partly | Yes |
| Check-connection-to-I-O-board-X | Check connection to I/O board X | Partly | Yes |
| d1 | Return temp. sensor contact faulty (status L) - temperature sensor short/open circuit, condenser inlet | Yes | Yes |
| E0 | Alarm table: Water flow failure (water flow failure 3 times) / Troubleshooting table: Flow switch error (E8 displayed 3 times; to be seen together with E8) | Yes | Yes |
| E1 | Alarm table: Line-to-line or zero phase error (three-phase models have this error code) / Troubleshooting table: Phase sequence error (only for three-phase units) | Yes | Yes |
| E1x.T1-failure | Failure on sensor E12.T1, E13.T1... flow | Partly | Yes |
| E1X.T1-high | High flow temperature E1X.T1 | Yes | Yes |
| E1x.T1-short | Short circuit on sensor E12.T1, E13.T1... flow | Partly | Yes |
| E1X.TT-comm | Check connection to room sensor E1X.TT (room controller) | No | Yes |
| E1X.TT.T5-failure | Failure on sensor E1X.TT.T5 room | No | Yes |
| E1X.TT.T5-short | Short circuit on sensor E1X.TT.T5 room | No | Yes |
| E2 | Alarm table: Communication error between user interface and hydraulic module / Troubleshooting table: Communication error between the user interface and the main hydraulic module control board | Yes | Yes |
| E2X-T8T9-delta | High temperature difference heat transfer fluid E2X | No | Yes |
| E2X-T10T11-delta | High temperature difference collector circuit E2X | No | Yes |
| E2X.F11 | Motor cut-out 1 E2X.F11, compressor | Yes | Yes |
| E2X.RHP | Tripped high pressure switch | Yes | Yes |
| E2X.RLP | Tripped low pressure switch | Yes | Yes |
| E2X.T6 | High hot gas temperature | Yes | Yes |
| E2X.T6-failure | Failure on sensor E2X.T6 hot gas | Yes | Yes |
| E2X.T6-short | Short circuit on sensor E2X.T6 hot gas | Yes | Yes |
| E2X.T8-aux-high | Electric additional heat shut down due to high temperature E2X.T8 | Partly | Yes |
| E2X.T8-failure | Failure on sensor E2X.T8 heat transfer fluid out | No | Yes |
| E2X.T8-info | High flow temperature E2X.T8 | Partly | Yes |
| E2X.T8-short | Short circuit on sensor E2X.T8 heat transfer fluid out | No | Yes |
| E2X.T9-failure | Failure on sensor E2X.T9 heat transfer fluid in | No | Yes |
| E2X.T9-short | Short circuit on sensor E2X.T9 heat transfer fluid in | No | Yes |
| E2X.T10 | Low temperature collector circuit in | Partly | Yes |
| E2X.T10-failure | Failure on sensor E2X.T10 | No | Yes |
| E2X.T10-short | Short circuit on sensor E2X.T10 | No | Yes |
| E2X.T11 | Low temperature collector circuit out | Partly | Yes |
| E2X.T11-failure | Failure on sensor E2X.T11 | No | Yes |
| E2X.T11-short | Short circuit on sensor E2X.T11 | No | Yes |
| E3 | Alarm table: Leaving water temperature sensor T1 failure / Troubleshooting table: Error of the backup heater's heat exchanger outlet T1 temperature sensor | Yes | Yes |
| E4 | Alarm table: Storage tank water temperature sensor T5 failure / Troubleshooting table: T5 DHW temperature sensor error | Partly | Yes |
| E5 | Alarm table: Unit temperature sensor T3 failure / Troubleshooting table: Error of the finned coil outlet T3 refrigerant temperature sensor in cooling mode | Yes | Yes |
| E6 | Alarm table: Unit room temperature sensor T4 failure / Troubleshooting table: T4 room temperature sensor error | Yes | Yes |
| E7 | Alarm table: Inertial storage tank sensor Tbt1 failure / Troubleshooting table: Tbt1 sensor error | Varies by model | Yes |
| E8 | Alarm table: Water flow failure (displayed three times and can be reset after minutes) / Troubleshooting table: Water flow-rate error | Yes | Yes |
| E9 | Alarm table: Temperature sensor Th failure / Troubleshooting table: Th suction pipe sensor error | Yes | Yes |
| E11.T1-failure | Failure on sensor E11.T1 flow | Partly | Yes |
| E11.T1-short | Short circuit on sensor E11.T1 flow | Partly | Yes |
| E21.E2 | Faulty electric heater E21.E2 | Partly | Yes |
| E21.RHP-info | Temporary heat pump stop E21.RHP | Partly | Yes |
| E21.RLP-info | Temporary heat pump stop E21.RLP | Partly | Yes |
| E41.F31 | Faulty protective anode E41.F31 | No | Yes |
| EA | Alarm table: Unit air temperature sensor Tp failure / Troubleshooting table: Tp discharge temperature sensor error | Yes | Yes |
| Eb | Alarm table: Tsolar sensor failure / Troubleshooting table: Solar panel sensor error (Tsolar) | Varies by model | Yes |
| EC | Alarm table: DHW additional storage tank sensor Tbt2 failure | Varies by model | Yes |
| Ed | Alarm table: Water temperature sensor Twin board replacement failure / Troubleshooting table: Tw_in entering water temperature sensor error | Yes | Yes |
| EE | Alarm table: EEprom hydraulic module failure / Troubleshooting table: EEPROM control board main hydraulic module control board failure | Yes | Yes |
| EF | System fault appliance PCB / basic controller (status L); hybrid control module component fault; EEPROM error in hybrid control module (display blank) | Yes | Yes |
| EK | Electric heater (EK) | Partly | Yes |
| Error-in-accessory-board | Alarm: Error in accessory board | Yes | Yes |
| Error-in-main-board-heating-system | Alarm: Error in main board, heating system | Yes | Yes |
| Error-in-multi-function-board | Alarm: Error in multi function board | Yes | Yes |
| Error-in-room-sensor-board-or-error-in-E12-T5-room-sensor-board | Alarm: Error in room sensor board or error in E12.T5 room sensor board | Yes | Yes |
| F1 | Alarm table: DC bus low voltage protection / Troubleshooting table: DC generatrix voltage too low | Yes | Yes |
| F5 | High pressure switch 63H | Yes | Yes |
| Failure-Short-circuit-on-sensor | Alarm window: Failure / Short circuit on sensor | Yes | Yes |
| Fault-in-I-O-card-control-cabinet-electric-boiler | Alarm window: Fault in I/O card control cabinet/electric boiler | Yes | Yes |
| Fault-on-additional-heater | Alarm: Fault on additional heater | Yes | Yes |
| Fault-on-electric-additional-heat | Alarm window: Fault on electric additional heat | Yes | Yes |
| Fault-on-electric-element | Alarm: Fault on electric element | Yes | Yes |
| Faulty-function-in-4-way-valve | Alarm window: Faulty function in 4-way valve | Yes | Yes |
| FIL | Filter is dirty. | No | Yes |
| Fill | Water pressure in the heating system is too low. | Partly | Yes |
| Freeze-protection-exchanger-T9-activated | Alarm: Freeze protection exchanger T9 activated | Yes | Yes |
| GT-sensor | Sensor fault (example GT1 return radiator; all sensors alarm the same way) | Yes | Yes |
| GT6 | Compressor temperature T6 (GT6) | Yes | Yes |
| GT8 | Heat transfer fluid out max T8 (GT8) | Yes | Yes |
| GT8-GT9 | High Heat transfer fluid delta T8/T9 (GT8/GT9) | Partly | Yes |
| GT9 | High return to the heat pump T9 (GT9) | Yes | Yes |
| GT10 | HTF in under limit T10 (GT10) | Yes | Yes |
| GT11 | HTF out under limit T11 (GT11) | Yes | Yes |
| H0 | Alarm table: Communication error between indoor unit and unit (continuous communication error for 10 seconds) / Communication error between unit and indoor unit (no communication in 10 seconds) / Troubleshooting table: Communication error between the main PCB B control board and the main hydraulic module control board | Yes | Yes |
| H1 | Alarm table: Communication error between unit and IR341 (unit and inverter module) / Troubleshooting table: Communication error between PCB A inverter module and the main PCB B control board | Yes | Yes |
| H01-5239 | DHW temp sensor TW1 fault | Partly | Yes |
| H01-5594 | Air in the system | Yes | Yes |
| H01-5803 | No power supply at compressor (Alarm) | Yes | Yes |
| H01-5805 | Current sensor fault (Alarm) | Yes | Yes |
| H01-5807 | IPM driver pin fault (Alarm) | Yes | Yes |
| H01-5809 | AC input zero cross error (Alarm) | Yes | Yes |
| H2 | Alarm table: Gas side refrigerant temperature sensor T2 failure / Troubleshooting table: Error of the plate heat exchanger inlet temperature sensor (T2) on the refrigerant side in cooling mode | Yes | Yes |
| H3 | Alarm table: Liquid side refrigerant temperature sensor T2B failure / Troubleshooting table: Error of the heat exchanger outlet temperature sensor (T2B) on the refrigerant side in cooling mode | Yes | Yes |
| H4 | Alarm table: After 3 L signals (L0/L1) in 1 hour, H4 appears, which cannot be reset. After H4 it is possible to check the last 3 L signals / Troubleshooting table: Three P6 protection activations | Yes | Yes |
| H5 | Alarm table: Temperature sensor Ta failure / Troubleshooting table: Ta internal temperature sensor error | Partly | Yes |
| H6 | Alarm table: DC fan failure / Troubleshooting table: DC fan error | Yes | Yes |
| H7 | Alarm table: Abnormal power supply voltage / Troubleshooting table: Main circuit voltage fault | Yes | Yes |
| H8 | Alarm table: High pressure sensor failure / Troubleshooting table: Pressure sensor error | Yes | Yes |
| H9 | Alarm table: Sensor Tw2 failure / Troubleshooting table: Tw2 sensor error | Partly | Yes |
| HA | Alarm table: Plate exchanger outlet temperature sensor failure / Troubleshooting table: Error of the TW_out leaving water temperature sensor of the plate heat exchanger | Yes | Yes |
| Hb | Alarm table: Three consecutive faults PP protection and Twout < 7 C; reset for power failure / Troubleshooting table: PP protection trips 3 times and Tw_out < 7 C | Yes | Yes |
| Hd | Alarm table: Communication error between slave and master (this error occurs when several units are connected in parallel) / Troubleshooting table: Communication error between master and slave units | Partly | Yes |
| HE | Alarm table: Communication error between hydraulic module and hydraulic module adapter board / Troubleshooting table: Communication error between main board and thermostat | Partly | Yes |
| Heat-pump-is-now-working-at-its-highest-permitted-temperature | Info window: Heat pump is now working at its highest permitted temperature | Partly | Yes |
| HF | Alarm table: Unit EEPROM failure / Troubleshooting table: Inverter module EEprom error | Yes | Yes |
| HH | Alarm table: H6 failure 10 consecutive times in 120 minutes (reset after shut down) / Troubleshooting table: H6 displayed 10 times in 2 hours | Yes | Yes |
| High-temperature-difference-heat-transfer-fluid | Warning window: High temperature difference heat transfer fluid | No | Yes |
| HL | Troubleshooting table: PFC module fault | Yes | Yes |
| HP | Alarm table: Cooling mode low pressure protection (in 1 hour, low pressure is below 0.6 MPa three consecutive times, can be reset automatically) / Troubleshooting table: Low pressure protection (Pe < 0.6) tripped 3 times in one hour | Yes | Yes |
| Hxx | Maintenance message, e.g. service interval of heat source elapsed | No | Yes |
| Is-the-heat-pump-fused-for-this-output | Warning window: Is the heat pump fused for this output? | No | Yes |
| L0 | Alarm table: DC compressor module error / Troubleshooting table: Compressor inverter module fault | Yes | Yes |
| L1 | Alarm table: DC bus low voltage protection / Troubleshooting table: Low voltage BUS protection of the inverter module | Yes | Yes |
| L2 | Alarm table: DC bus high voltage protection / Troubleshooting table: High voltage BUS protection of the inverter module | Yes | Yes |
| L4 | Alarm table: MC/synchronisation/closed circuit error / Troubleshooting table: MCE protection | Yes | Yes |
| L5 | Alarm table: Zero speed protection / Troubleshooting table: Speed 0 protection | Yes | Yes |
| L7 | Alarm table: Phase sequence error protection / Troubleshooting table: Phase sequence error | Yes | Yes |
| L8 | Alarm table: Protection for when the preceding and following speed variation is >15 Hz / Troubleshooting table: Compressor frequency variation greater than 15 Hz in 1 sec | Yes | Yes |
| L9 | Alarm table: Protection for when the difference between the set speed and the operating speed is >15 Hz / Troubleshooting table: Compressor frequency difference to target greater than 15 Hz | Yes | Yes |
| Low-mains-voltage | Alarm: Low mains voltage | Yes | Yes |
| Low-pressure-collector-circuit | Low pressure collector circuit | Yes | Yes |
| Low-temperature-in-condenser | Alarm window: Low temperature in condenser | Yes | Yes |
| LP | Low pressure switch (LP) | Yes | Yes |
| Max-flow-temperature-heating-system | Alarm: Max flow temperature, heating system | Yes | Yes |
| Maximum-flow-temperature-additional-heat | Info: Maximum flow temperature, additional heat | Partly | Yes |
| Maximum-flow-temperature-heat-pump | Info: Maximum flow temperature, heat pump | Partly | Yes |
| Maximum-working-temperature-additional-heat | Info: Maximum working temperature additional heat | Partly | Yes |
| Maximum-working-temperature-heat-pump | Warning: Maximum working temperature heat pump | No | Yes |
| MB1 | Motor cut-out compressor | Yes | Yes |
| MB2 | Motor cut-out HTF pump | Yes | Yes |
| No-pressure-in-system | Alarm: No pressure in system | Yes | Yes |
| Overheat-protection-tripped-hot-water-electric-heater | Overheat protection tripped hot water electric heater | Partly | Yes |
| Overloaded-transformer | Alarm: Overloaded transformer | Yes | Yes |
| P0 | Alarm table: Low pressure protection / Troubleshooting table: Low pressure protection | Yes | Yes |
| P1 | Alarm table: Discharge temperature/high pressure control switch protection / Troubleshooting table: High pressure protection | Yes | Yes |
| P3 | Alarm table: Compressor overcurrent protection / Troubleshooting table: Compressor over current protection | Yes | Yes |
| P4 | Alarm table: Exhaust air temperature overheating protection Tp / Troubleshooting table: Protection for high discharge temperature | Yes | Yes |
| P5 | Alarm table: Twin-Twout, Twout-Twin protection or water supply temperature too high / Troubleshooting table: Protection against high temperature difference between entering and leaving water of the plate heat exchanger | Yes | Yes |
| P6 | Alarm table: Module protection (IPDU and IR341) / Troubleshooting table: Module protection | Yes | Yes |
| P9 | Troubleshooting table: Fan protection | Yes | Yes |
| Pb | Alarm table: Antifreeze (this is not a protection, the alarm light does not flash), the remote control does not display Pb, but displays the antifreeze icon / Troubleshooting table: Antifreeze protection | Partly | Yes |
| Pd | Alarm table: Unit T3 over-temperature protection / Troubleshooting table: Protection for high refrigerant outlet temperature in the finned coil in cooling mode | Yes | Yes |
| PP | Alarm table: Abnormal temperature difference between entering and leaving water / Troubleshooting table: The inlet water temperature is higher than the outlet water temperature in heating mode | Yes | Yes |
| Screed-drying-set-point-value-for-heating-not-reached | Alarm: Screed drying set point value for heating not reached | Varies by model | Yes |
| softstarter | Soft starter alarm (red LED flashes 2/3/4/5) | Yes | Yes |
| T2-failure | Failure on sensor T2 outdoor | No | Yes |
| T2-short | Short circuit on sensor T2 outdoor | No | Yes |
| T3-failure | Failure on sensor T3 hot water | Partly | Yes |
| T3-short | Short circuit on sensor T3 hot water | Partly | Yes |
| T6-High-hot-gas-temperature | Alarm window: T6 High hot gas temperature | Yes | Yes |
| T8-High-flow-temperature | Alarm window: T8 High flow temperature | Yes | Yes |
| T8-high-flow-temperature-or-T71-high-flow-temperature | Alarm: T8 high flow temperature or T71 high flow temperature | Yes | Yes |
| Temporary-stop-of-compressor-operation | Info window: Temporary stop of compressor operation | Partly | Yes |
| Temporary-stop-of-hot-water-production | Info window: Temporary stop of hot water production | Partly | Yes |
| The-heat-pump-is-now-working-in-anti-freeze-mode | The heat pump is now working in anti-freeze mode | No | Yes |
| This-setting-means-that-additional-heat-can-take-over-operation | Info window: This setting means that additional heat can take over operation | Partly | Yes |
| Too-cold-for-heat-pump-operation | Info: Too cold for heat pump operation | Partly | Yes |
| Too-high-boot-count-I-O-board-BAS-x | Too high boot count I/O board BAS x | Yes | Yes |
| Too-high-return-temp | Info: Too high return temp | Partly | Yes |
| Too-hot-for-heat-pump-operation | Info: Too hot for heat pump operation | Partly | Yes |
| Too-low-flow-temperature | Info: Too low flow temperature | Partly | Yes |
| Too-short-changeover-time-for-floor-heating | Warning: Too short changeover time for floor heating | No | Yes |
| Tripped-high-pressure-switch | Alarm window: Tripped high pressure switch | Yes | Yes |
| Tripped-low-pressure-switch | Alarm window: Tripped low pressure switch | Yes | Yes |
| Tripped-motor-cut-out | Alarm window: Tripped motor cut-out | Yes | Yes |
| Tripped-motor-cut-out-fan | Alarm window: Tripped motor cut-out fan | Yes | Yes |
| U1 | High pressure too high (63H has responded) | Yes | Yes |
| U2 | Excessively high temperature at hot gas sensor TH4 and compressor sensor TH32 (U2 (1) hot gas too high; U2 (2) insufficient refrigerant; U2 (3) compressor temperature too high) | Yes | Yes |
| U3 | Open / short circuit on hot gas temperature sensor TH4 or compressor temperature sensor TH32 | Yes | Yes |
| U4 | Open / short circuit on external unit temperature sensors (TH3, TH32, TH33, TH6, TH7 and TH8) | Yes | Yes |
| U5 | Temperature fault on inverter radiator panel | Yes | Yes |
| U6 | Power module in inverter circuit faulty | Yes | Yes |
| U7 | Superheating not possible through hot gas temperature being too low | Yes | Yes |
| U8 | Speed fault at the fan motor | Yes | Yes |
| U9 | Inverter over or undercurrent and fault in the serial PCB communication | Yes | Yes |
| Ud | Overheating protection (overload protection, fan motor fault) | Yes | Yes |
| UF | Safety device to protect against compressor overcurrent: compressor blocked | Yes | Yes |
| UH | Current sensor fault | Yes | Yes |
| UP | Compressor overcurrent - safety device has responded | Yes | Yes |