Vaillant · A major brand in the UK. 375 codes across 5 product families, each taken from the manufacturer’s manuals. Vaillant technical support ↗
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375 codes
| Code | Meaning | Stops? | Homeowner check? |
|---|---|---|---|
| 1 | XXX address YY not accessible (eBUS component, e.g. VR 60, not recognised) | Partly | Yes |
| 4 | XXX address YY sensor fault ZZZ (sensor on an eBUS component) | Partly | Yes |
| 5 | XXXX setpoint not achieved | Partly | Yes |
| 20 | Frost protection heat source monitoring source outlet (T3-T8 difference too large) | Partly | Yes |
| 22 | Frost protection heat source over. source outlet (source outlet T8 below freeze protection temperature) | Partly | Yes |
| 26 | Overheating on compressor pressure side | No | Yes |
| 27 | Coolant (refrigerant) pressure too high - high pressure switch tripped (30 bar g) | Partly | Yes |
| 28 | Coolant (refrigerant) pressure too low - low pressure switch tripped (1.25 bar g) | Partly | Yes |
| 29 | Coolant pressure outside the range | Partly | Yes |
| 32 | Error heat source sensor T8 (short circuit) | Yes | Yes |
| 33 | Error heat circuit pressure sensor (short circuit) | Yes | Yes |
| 34 | Error brine pressure sensor (short circuit) | Yes | Yes |
| 36 | Low brine pressure (warning, < 0.6 bar) | No | Yes |
| 40 | Error comp outlet sensor T1 (short circuit) | Yes | Yes |
| 41 | Error heat source sensor T3 (short circuit) | Yes | Yes |
| 42 | Error HP return sensor T5 (short circuit) | Yes | Yes |
| 43 | Error HP flow sensor T6 (short circuit) | Yes | Yes |
| 44 | Error external sensor AF (outside temperature sensor short circuit) | Yes | Yes |
| 45 | Error DHW tank sensor SP (short circuit) | Yes | Yes |
| 46 | Error HB flow sensor VF1 (buffer cylinder upper sensor short circuit) | Yes | Yes |
| 47 | Error HB return sensor RF1 (buffer cylinder lower sensor short circuit) | Yes | Yes |
| 48 | Error flow sensor VF2 (short circuit) | Yes | Yes |
| 52 | Sensors are not suited to the hydraulic plan | Yes | Yes |
| 60 | Frost protection heat source monitoring source outlet - error 20 occurred three times in a row | Yes | Yes |
| 62 | Frost protection heat source monitoring source outlet - error 22 occurred three times in a row | Yes | Yes |
| 72 | Flow temperature too high for underfloor heating (VF2 above max. HK temp + compressor hysteresis + 2 K for 15 min; default 52 °C) | Yes | Yes |
| 81 | Coolant pressure too high - error 27 occurred three times in a row | Yes | Yes |
| 83 | Coolant pressure too low, check heat source - error 28 occurred three times in a row | Yes | Yes |
| 84 | Coolant pressure outside the range - error 29 occurred three times in a row | Yes | Yes |
| 90 | Heating system pressure too low (< 0.5 bar; restarts automatically above 0.7 bar) | Yes | Yes |
| 91 | Brine pressure too low (< 0.2 bar; restarts automatically above 0.4 bar) | Yes | Yes |
| 94 | Phase loss - check circuit breaker (one or more phases dropped out) | Yes | Yes |
| 95 | Wrong direction of rotation - change compressor phases (phase sequence not correct) | Yes | Yes |
| 96 | Error - coolant (refrigerant) circuit pressure sensor (short circuit) | Yes | Yes |
| 97 | No power for compressor | Yes | Yes |
| 200 | Comfort protection (limp home) mode code 200 - Sensor fault: Temp. air inlet | Partly | Yes |
| 500 | Product is waiting | Partly | Yes |
| 501 | Pump prerun before heating mode | No | Yes |
| 502 | Pump prerun correct in heating mode | No | Yes |
| 503 | Water temperature/compatibility test for heating mode setting | No | Yes |
| 504 | Start of heating mode activated | No | Yes |
| 505 | Maximum speed of pump prerun in heating mode | No | Yes |
| 506 | Fan pre-run in heating mode | No | Yes |
| 507 | 4-port valve in heating position | No | Yes |
| 508 | Electronic expansion valve in heating position | No | Yes |
| 509 | Compressor start requirement in heating mode | No | Yes |
| 510 | Product in heating mode | No | Yes |
| 511 | Product in domestic hot water mode | No | Yes |
| 512 | Heating mode: Water temperature exceeded | No | Yes |
| 513 | Domestic hot water mode: Water temperature exceeded | No | Yes |
| 514 | Pump overrun after heating mode | No | Yes |
| 515 | Pump prerun before thawing | No | Yes |
| 516 | Product in thawing mode | No | Yes |
| 517 | Pump overrun after thawing | No | Yes |
| 518 | Pump operated by remote control (auxiliary) | No | Yes |
| 519 | Compressor's oil temperature too low for operation | Partly | Yes |
| 530 | Pump prerun before cooling mode | No | Yes |
| 531 | Pump prerun correct in cooling mode | No | Yes |
| 532 | Water temperature/compatibility test for cooling mode setting | No | Yes |
| 533 | Start of cooling mode activated | No | Yes |
| 534 | Maximum speed of pump prerun | No | Yes |
| 535 | Fan pre-run | No | Yes |
| 536 | 4-port valve in cooling position | No | Yes |
| 537 | Electronic expansion valve in cooling position | No | Yes |
| 538 | Compressor start requirement in cooling mode | No | Yes |
| 539 | Product in cooling mode | No | Yes |
| 540 | Cooling mode: Water temperature exceeded | No | Yes |
| 541 | Pump overrun after cooling mode | No | Yes |
| 550 | Fault: Pressure compensation | Partly | Yes |
| 551 | Fault: Pressure switch | Partly | Yes |
| 552 | Fault detected: Operating pressure | Partly | Yes |
| 553 | Fault detected: Initial operating pressure not OK | Partly | Yes |
| 554 | Low-tariff power supply failure | Partly | Yes |
| 555 | Refrigerant circuit pressure not in the permissible range/high pressure : low pressure ratio too low | Partly | Yes |
| 556 | Refrigerant circuit pressure not in the permissible range/condensation rate too low | Partly | Yes |
| 557 | Refrigerant circuit pressure not in the permissible range/evaporation rate too high | Partly | Yes |
| 558 | Refrigerant circuit pressure not in the permissible range/condensation rate too high | Partly | Yes |
| 559 | Refrigerant circuit pressure too low | Partly | Yes |
| 560 | Compressor outlet overheated | Partly | Yes |
| 561 | Fault: Compressor inlet temperature sensor | Partly | Yes |
| 562 | Fault: Compressor outlet temperature sensor | Partly | Yes |
| 563 | Fault: Plate heat exchanger temperature sensor | Partly | Yes |
| 564 | Fault: Fin-type heat exchanger temperature sensor | Partly | Yes |
| 565 | Fault: Outdoor temperature sensor | Partly | Yes |
| 566 | Fault: Flow temperature sensor | Partly | Yes |
| 567 | Fault: Return temperature sensor | Partly | Yes |
| 568 | Fault: High-pressure sensor in refrigerant circuit | Partly | Yes |
| 569 | Fault: Frequency converter low-voltage bus | Partly | Yes |
| 570 | Fault: Frequency converter switched off | Partly | Yes |
| 571 | Fault: Frequency converter overheated | Partly | Yes |
| 572 | Fault: Frequency converter overcurrent | Partly | Yes |
| 573 | Fault: Frequency converter voltage too low | Partly | Yes |
| 574 | Fault: Frequency converter voltage too high | Partly | Yes |
| 575 | Fault: Frequency converter inverter | Partly | Yes |
| 576 | Fault: Frequency converter heat sensor | Partly | Yes |
| 577 | Fault: Frequency converter overload | Partly | Yes |
| 578 | Fault: Fan PCB | Partly | Yes |
| 579 | Communication fault: eBUS | Partly | Yes |
| 580 | Fault: Flow rate | Partly | Yes |
| 581 | Communication error with frequency converter | Partly | Yes |
| 582 | Compressor overcurrent fault | Partly | Yes |
| 584 | Fault: Electronic expansion valve | Partly | Yes |
| 585 | Fan speed too low | Partly | Yes |
| 588 | Coding resistor fault | Partly | Yes |
| 589 | Fault: Underfloor protective circuit | Partly | Yes |
| 590 | Fault: 4-port valve | Partly | Yes |
| 599 | Fault: Product | Partly | Yes |
| CONNECTION-FAULT-ACCESSORY-MODULES | Connection fault: Accessory modules | Yes | Yes |
| CONNECTION-FAULT-HEAT-PUMP | Connection fault: Heat pump | Yes | Yes |
| F.022 | Building circuit: Water press. too low | Yes | Yes |
| F.037 | Fan fault | Yes | Yes |
| F.042 | Fault: Coding resistor | Yes | Yes |
| F.070 | Fault: Invalid Device Specific Number | Yes | Yes |
| F.073 | Sensor fault: Building circ. water pressure | Yes | Yes |
| F.086 | Surface-mounted thermostat opened | Yes | Yes |
| F.094 | Fault: Vortex | Yes | Yes |
| F.103 | Fault: Spare part ident. | Yes | Yes |
| F.509 | Ventilation unit communication interrupted | No | Yes |
| F.511 | HP control module communication interrupted | No | Yes |
| F.514 | Sensor fault: Compr. inlet temp. | Yes | Yes |
| F.517 | Sensor fault: Compr. outlet temp. | Yes | Yes |
| F.519 | Sensor fault: Building circuit return temp. | Yes | Yes |
| F.520 | Sensor fault: Building circuit flow temp. | Yes | Yes |
| F.521 | Outdoor temperature sensor signal invalid | Partly | Yes |
| F.523 | Sensor fault: VF1 | Yes | Yes |
| F.526 | Sensor fault: EEV outlet temp. | Yes | Yes |
| F.532 | Building circuit: Flow rate too low | Yes | Yes |
| F.536 | Compressor outlet temp. too high | Yes | Yes |
| F.537 | High-pressure switch opened | Yes | Yes |
| F.539 | Refrigerant pressure too low | Yes | Yes |
| F.546 | Sensor fault: High pressure | Yes | Yes |
| F.554 | Refrigerant pressure not in operating range | Yes | Yes |
| F.582 | Fault: EEV | Yes | Yes |
| F.583 | Building circuit: Flow temp. too low | Yes | Yes |
| F.585 | Sensor fault: Capac. outlet temp. | Yes | Yes |
| F.685 | Communication fault: eBUS | Yes | Yes |
| F.700 | Temp. sensor fault: EEV environment cir. | Yes | Yes |
| F.701 | Sensor fault: Env. circuit inlet temp. | Yes | Yes |
| F.702 | Sensor fault: Env. circuit outlet temp. | Yes | Yes |
| F.703 | Sensor fault: Low pressure | Yes | Yes |
| F.704 | Sensor fault: Build. circ. pressure | Yes | Yes |
| F.705 | Sensor fault: Env. circuit pressure | Yes | Yes |
| F.706 | Sensor fault: Building flow rate | Yes | Yes |
| F.707 | Connection error: Disp. not recognised | Yes | Yes |
| F.708 | Connection error: Fan unit 1: | Yes | Yes |
| F.710 | Env. circuit: Outlet temp. too low | Yes | Yes |
| F.714 | Environment circuit: Pressure too low | Yes | Yes |
| F.715 | Env. circuit: Fault contact: Pump open | Yes | Yes |
| F.718 | Fan unit 1: Fan blocked | Yes | Yes |
| F.719 | Fan unit 1: Safety cut-out open | Partly | Yes |
| F.723 | Building circuit: Pressure too low | Yes | Yes |
| F.724 | Sensor fault: Fan unit 1 fan inlet temp. | Yes | Yes |
| F.725 | Sensor fault: Fan unit 1 brine flow temp. | Yes | Yes |
| F.726 | Compressor protector switch opened | Yes | Yes |
| F.729 | Compressor outlet temperature too low | Yes | Yes |
| F.730 | Low pressure switch opened | Yes | Yes |
| F.731 | High-pressure switch open | Yes | Yes |
| F.732 | Compressor outlet temperature too high | Yes | Yes |
| F.733 | Evaporation temperature too low | Yes | Yes |
| F.734 | Condensation temperature too low | Yes | Yes |
| F.735 | Evaporation temperature too high | Yes | Yes |
| F.737 | Condensation temperature too high | Yes | Yes |
| F.740 | Environment circuit: Inlet temp. too low | Yes | Yes |
| F.741 | Building circuit: Return temp. too low | Yes | Yes |
| F.742 | Environment circuit: Inlet temp. too high | Yes | Yes |
| F.743 | Building circuit: Return temp. too high | Yes | Yes |
| F.750 | Connection fault: Compressor | Yes | Yes |
| F.751 | Compressor: Overcurrent fault | Yes | Yes |
| F.752 | Fault: Frequency converter | Yes | Yes |
| F.753 | Connection fault: Freq. conv. n.recogn. | Yes | Yes |
| F.754 | Fault: Fan unit | Yes | Yes |
| F.755 | Fault: 4-port valve position not correct | Yes | Yes |
| F.774 | Sensor fault: Air inlet temp. | Yes | Yes |
| F.782 | Connection error: Fan unit 2: | Yes | Yes |
| F.783 | Connection error: Terminal block (TMB) | Yes | Yes |
| F.784 | Connection error: ICL | Yes | Yes |
| F.785 | Fan unit 2: Fan blocked | Yes | Yes |
| F.786 | Fan unit 2: Safety cut-out open | Partly | Yes |
| F.787 | Environment circuit: Pressure mon. open | Yes | Yes |
| F.788 | Building circuit: Pump fault | Yes | Yes |
| F.789 | Sensor fault: Fan unit 2 fan inlet temp. | Yes | Yes |
| F.790 | Sensor fault: Fan unit 2 brine flow temp. | Yes | Yes |
| F.792 | Sensor fault: VI inlet temp. | Yes | Yes |
| F.793 | Sensor fault: EEV-VI outlet temp. | Yes | Yes |
| F.797 | Sensor fault: Cooling flow temp. | Yes | Yes |
| F.798 | Sensor fault: Well inlet temp. | Yes | Yes |
| F.799 | Sensor fault: Well outlet temp. | Yes | Yes |
| F.817 | Freq. converter fault: Compressor | Yes | Yes |
| F.818 | Freq. converter fault: Mains voltage | Yes | Yes |
| F.819 | Freq. converter fault: Overheating | Yes | Yes |
| F.820 | Connection fault: Building circuit pump | Yes | Yes |
| F.821 | Sensor fault: Immers. heater flow temp. | Yes | Yes |
| F.823 | Hot gas temperature switch open | Yes | Yes |
| F.824 | Building circuit : Brinepressure too low | Yes | Yes |
| F.825 | Sensor fault: Capac. inlet temp. | Yes | Yes |
| F.900 | Internet module communication interrupted | No | Yes |
| F.1100 | Immersion heater: Safety cut-out open | Partly | Yes |
| F.1117 | Compressor: Phase failure | Yes | Yes |
| F.1118 | Compressor: Incorrect phase seq. | Yes | Yes |
| F.1119 | Compressor: ICL fault | Yes | Yes |
| F.1120 | Immersion heater: Phase failure | Yes | Yes |
| F.1191 | Heat generator 1 communication interrupted (can be heat generator 1 to 8) | Partly | Yes |
| F.1212 | FM3 address 1 communication interrupted (can be address 1 to 3) | No | Yes |
| F.1218 | FM5 communication interrupted | No | Yes |
| F.1219 | Remote control 1 communication interrupted (can be address 1 to 3) | No | Yes |
| F.1227 | Domestic hot water station communication interrupted | No | Yes |
| F.1228 | Solar pump station communication interrupted | No | Yes |
| F.1231 | FM3 configuration [1] not correct (can be address 1 to 3) | No | Yes |
| F.1237 | Mixer module not supported | No | Yes |
| F.1238 | Solar module not supported | No | Yes |
| F.1239 | Remote control not supported | No | Yes |
| F.1240 | Basic system diagram code not correct | Partly | Yes |
| F.1244 | FM3 missing | No | Yes |
| F.1245 | DHW temperature sensor S1 missing at FM3 | No | Yes |
| F.1246 | Solar pump 1 reports faults (can be solar pump 1 or 2) | No | Yes |
| F.1248 | Shift-load cylinder not supported | No | Yes |
| F.1249 | HP control module MO2 configuration not correct | No | Yes |
| F.1251 | FM5 configuration not correct | No | Yes |
| F.1257 | FM3 configuration [1] MO not correct (can be address 1 to 3) | No | Yes |
| F.1263 | FM5 configuration MO not correct | No | Yes |
| F.1288 | Fault: SP1 cylinder temperature sensor | Yes | Yes |
| F.1361 | System control room temperature sensor signal invalid | No | Yes |
| F.1363 | Room temperature sensor signal on remote control 1 invalid (can be address 1 to 3) | No | Yes |
| F.5000 | S1 sensor signal at FM3 address 1 invalid (can be S1 to S7 and address 1 to 3) | No | Yes |
| F.5021 | S1 sensor signal at FM5 invalid (can be S1 to S13) | No | Yes |
| F.5034 | Heat generator 1 reports faults (can be heat generator 1 to 8) | Partly | Yes |
| F.5050 | Ventilation unit reports faults | No | Yes |
| F.5051 | HP control module reports faults | No | Yes |
| F.5056 | Assignment of remote control 1 missing (can be address 1 to 3) | No | Yes |
| F.5060 | Zone activation missing | Partly | Yes |
| F.9998 | Connection fault: Heat pump | Yes | Yes |
| M.23 | Status external current anode | No | Yes |
| M.32 | Building circuit: Waterpress. Low | No | Yes |
| M.33 | Fan unit: Cleaning required | No | Yes |
| M.34 | Environment circuit: Pressure low | No | Yes |
| M.49 | Environment circuit: Brine lines inverted | No | Yes |
| M.200 | Building circuit : Brine pressure low | No | Yes |
| M.201 | Sensor fault: Cylinder temperature | No | Yes |
| M.202 | Sensor fault: System temperature | No | Yes |
| M.203 | Connection fault: Disp. not recognised | No | Yes |
| MYVAILLANT-CONNECT-LED-GREEN | Ready for operation but not connected to the Internet | No | Yes |
| MYVAILLANT-CONNECT-LED-RED | Internet connection has been disconnected / fault | No | Yes |
| S.34 | Heating mode: Frost protection If the measured outdoor temperature falls below XX °C, the temperature of the heating circuit's flow and return is monitored. If the temperature difference exceeds the set value, the pump and compressor are started without a heat demand. | No | Yes |
| S.91 | Service message: Demo mode | No | Yes |
| S.100 | Standby There is no heat demand or cooling demand. Standby 0: Outdoor unit. Standby 1: Indoor unit | No | Yes |
| S.101 | Heating: Compressor shutdown The heat demand is met, the demand is ended by the system control and the heat deficit is offset. The compressor is switched off. | No | Yes |
| S.102 | Heating: Compressor blocked The compressor is blocked for heating mode because the heat pump is outside of its application limits. | Partly | Yes |
| S.103 | Heating: Prerun The start conditions for the compressor in heating mode are checked. Start the other actuators for heating mode. | No | Yes |
| S.104 | Heating: Compressor active The compressor works in order to meet the heat demand. | No | Yes |
| S.107 | Heating: Overrun The heat demand is met, the compressor is switched off. The pump and fan overrun. | No | Yes |
| S.111 | Cooling: Compressor shutdown The cooling demand is met, the demand is ended by the system control. The compressor is switched off. | No | Yes |
| S.112 | Cooling: Compressor blocked The compressor is blocked for cooling mode because the heat pump is outside of its application limits. | Partly | Yes |
| S.113 | Cooling: Compressor mode prerun The start conditions for the compressor in cooling mode are checked. Start the other actuators for cooling mode. | No | Yes |
| S.114 | Cooling: Compressor active The compressor works in order to meet the cooling demand. | No | Yes |
| S.117 | Cooling: Compressor mode overrun The cooling demand is met, the compressor is switched off. The pump and fan overrun. | No | Yes |
| S.118 | Cooling: Pre-run | No | Yes |
| S.119 | Cooling: Mixer active | No | Yes |
| S.125 | Heating: Immersion heater active The external back-up heater is used in heating mode. | No | Yes |
| S.131 | Hot water: Compressor shutdown | No | Yes |
| S.132 | Domestic hot water: Compressor blocked The compressor is blocked for domestic hot water mode because the heat pump is outside of the application limits. | Partly | Yes |
| S.133 | Domestic hot water: Prerun The start conditions for the compressor in domestic hot water mode are checked. Start the other actuators for domestic hot water mode. | No | Yes |
| S.134 | Domestic hot water: Compressor active The compressor works in order to meet the domestic hot water demand. | No | Yes |
| S.135 | Domestic hot water: Immersion heater active The external back-up heater is used in domestic hot water mode. | No | Yes |
| S.137 | Domestic hot water: Overrun The domestic hot water demand is met, the compressor is switched off. The pump and fan overrun. | No | Yes |
| S.141 | Heating: Immersion heater shutdown The heat demand is met, the external back-up heater is switched off. | No | Yes |
| S.142 | Heating: Immersion heater blocked The external back-up heater is blocked for heating mode. | Partly | Yes |
| S.151 | Domestic hot water: Immersion heater shutdown The domestic hot water demand is met, the external back-up heater is switched off. | No | Yes |
| S.152 | Domestic hot water: Immersion heater blocked The external back-up heater is blocked for domestic hot water mode. | Partly | Yes |
| S.170 | Compressor: Phase failure | Partly | Yes |
| S.171 | Compressor: Incorrect phase seq. | Partly | Yes |
| S.172 | Compressor: ICL fault | Partly | Yes |
| S.173 | Anti-cycling time for the energy supply company The mains voltage supply is interrupted by the energy supply company. The maximum anti-cycling time is set in the configuration. | Partly | Yes |
| S.176 | External electrical power limitation is active The heat pump or the electric back-up heater is limited by the energy supply company. | No | Yes |
| S.201 | Check program: Purging of env. circuit active | No | Yes |
| S.202 | Check programme: Purging of building circuit active The building circuit pump is actuated in cyclical intervals, alternately in heating mode and domestic hot water mode. | No | Yes |
| S.203 | Actuator test active The sensor and actuator test is currently operating. | No | Yes |
| S.211 | Connection error: Display not recognised | Partly | Yes |
| S.212 | Connection fault: Control not recognised System control was previously detected but the connection is broken. Check the eBUS connection to the system control. It can only be operated with the heat pump's additional functions. | Partly | Yes |
| S.213 | Connection error: Fan 1 not recognised | Partly | Yes |
| S.214 | Connection error: Fan 2 not recognised | Partly | Yes |
| S.215 | Connection error: TMB not recognised | Partly | Yes |
| S.216 | Connection error: ICL not recognised | Partly | Yes |
| S.240 | Compr. oil temp. too low, environment too cold The compressor heating is switched on. The unit does not start up. | Partly | Yes |
| S.242 | Environment circuit: Outlet temperature too low | Partly | Yes |
| S.246 | Environment circuit: Pressure too low | Partly | Yes |
| S.247 | Environment circuit: Fault cont.: Pump open | Partly | Yes |
| S.248 | Fan unit: De-icing with fan only | No | Yes |
| S.249 | Fan unit: De-icing with de-icer | No | Yes |
| S.252 | Fan unit 1: Fan blockedIf the fan speed is 0 rpm, the heat pump is switched off for 15 minutes and then restarted. If the fan does not start up after four unsuccessful restarts, the heat pump is switched off and the fault message F.718 … | Partly | Yes |
| S.253 | Fan unit 1: Safety cut-out open | Partly | Yes |
| S.254 | Fan unit 1: De-icing takes too long | Partly | Yes |
| S.255 | Fan unit 1: Air inlet temp. too high The compressor does not start because the outdoor temperature at the fan is above the application limits. Heating mode: > 43 °C. Domestic hot water mode: > 43 °C. Cooling mode: > 46 °C. | Partly | Yes |
| S.256 | Fan unit 1: Air inlet temp. too low The compressor does not start because the outdoor temperature at the fan is below the application limits. Heating mode: < -20 °C. Domestic hot water mode: < -20 °C. Cooling mode: < 15 °C. | Partly | Yes |
| S.260 | Fan unit 2: Fan blockedIf the fan speed is 0 rpm, the heat pump is switched off for 15 minutes and then restarted. If the fan does not start up after four unsuccessful restarts, the heat pump is switched off and the fault message F.785 … | Partly | Yes |
| S.261 | Fan unit 2: Safety cut-out open | Partly | Yes |
| S.262 | Fan unit 2: De-icing takes too long | Partly | Yes |
| S.263 | Fan unit 2: Air inlet temp. too high | Partly | Yes |
| S.264 | Fan unit 2: Air inlet temp. too low | Partly | Yes |
| S.265 | Environment circuit: Pressure monitor open | Partly | Yes |
| S.266 | Environment circuit: Outlet temperature too high | Partly | Yes |
| S.272 | Building circuit: Remaining feed head limit active The remaining feed head that is set under the configuration is reached. | Partly | Yes |
| S.273 | Building circuit: Flow temperature too low The flow temperature that is measured in the building circuit is below the application limits. | Partly | Yes |
| S.274 | Building circuit: Pressure too low | Partly | Yes |
| S.275 | Building circuit: Flow rate too low Building circuit pump defective. All consumers in the heating system are closed. The values fall below the specific minimum volume flows. Check that the dirt filter is permeable. Check the stopcocks and thermostatic valves. Ensure that the flow rate … | Partly | Yes |
| S.276 | Building circuit: Lockout contact S20 open Contact S20 is open at the heat pump's main PCB. Incorrect limit thermostat setting. Flow temperature sensor (heat pump, gas-fired boiler, system sensor) measures values that deviate downwards. Adjust the maximum flow temperature for the direct heating circuit via … | Partly | Yes |
| S.277 | Building circuit: Pump fault If the building circuit pump is inactive, the heat pump is switched off for 10 minutes and is then restarted. If the building circuit pump does not start up after three unsuccessful restarts, the heat pump is switched off and the … | Partly | Yes |
| S.280 | Freq. converter fault: Compressor The compressor motor or wiring is defective. | Partly | Yes |
| S.281 | Freq. converter fault: Mains voltage There is overvoltage or undervoltage. | Partly | Yes |
| S.282 | Freq. converter fault: Overheating If the cooling of the frequency inverter is not sufficient, the heat pump is switched off for one hour and then restarted again. If the cooling is not sufficient after three unsuccessful restarts, the heat pump is switched off and the … | Partly | Yes |
| S.283 | De-icing time too long If the de-icing takes longer than 15 minutes, the heat pump is restarted. If the time for the de-icing is still not sufficient after three unsuccessful restarts, the heat pump is switched off and the fault message F.741 is displayed.► Check … | Partly | Yes |
| S.284 | De-icing flow temperature too low If the flow temperature is below 5 °C, the heat pump is restarted. If the flow temperature is still not sufficient after three unsuccessful restarts, the heat pump is switched off and the fault message F.741 is displayed.► Check whether … | Partly | Yes |
| S.285 | Compressor outlet temperature too low Compressor outlet temperature is too low | Partly | Yes |
| S.286 | Hot gas temperature switch open If the hot gas temperature is above 119 °C +5 K, the heat pump is switched off for one hour and then restarted again. If the hot gas temperature has not fallen after three unsuccessful restarts, the heat pump is … | Partly | Yes |
| S.287 | Fan 1: Wind Before starting, the fan rotates at a speed of 50 rpm or higher. This may be caused by a strong outside wind. | No | Yes |
| S.288 | Fan 2: Wind Before starting, the fan rotates at a speed of 50 rpm or higher. This may be caused by a strong outside wind. | No | Yes |
| S.289 | Current limit active The outdoor unit's power consumption is reduced, the compressor speed is reduced. The compressor's operating current exceeds the limit value that is set under the configuration. (for 3 kW, 5 kW, 7 kW units: <16 A; for 10 kW, 12 kW units: … | Partly | Yes |
| S.290 | Switch-on delay active The compressor's switch-on delay is active. | Partly | Yes |
| S.302 | High-pressure switch open If the pressure in the refrigerant circuit exceeds the application limit, the heat pump is switched off for 15 minutes and is then restarted again. If the pressure remains too high after four unsuccessful restarts, the fault message F.731 is displayed. | Partly | Yes |
| S.303 | Compressor outlet temperature too high The operating characteristics have been exited. The heat pump is restarted. | Partly | Yes |
| S.304 | Evaporation temperature too low The operating characteristics have been exited. The heat pump is restarted. | Partly | Yes |
| S.305 | Condensation temperature too low The operating characteristics have been exited. The heat pump is restarted. | Partly | Yes |
| S.306 | Evaporation temperature too high The operating characteristics have been exited. The heat pump is restarted. | Partly | Yes |
| S.308 | Condensation temperature too high The operating characteristics have been exited. The heat pump is restarted. | Partly | Yes |
| S.311 | Environment circuit: Inlet temperature too low | Partly | Yes |
| S.312 | Building circuit: Return temperature too low Return temperature in the building circuit too low for compressor to start. Heating: Return temperature < 5 °C. Cooling: Return temperature < 10 °C. Cooling: Check that the 4-port diverter valve works correctly. | Partly | Yes |
| S.313 | Environment circuit: Inlet temperature too high | Partly | Yes |
| S.314 | Building circuit: Return temperature too high Return temperature in the building circuit too high for the compressor to start. Heating: Return temperature > 56 °C. Cooling: Return temperature > 35 °C. Cooling: Check that the 4-port diverter valve works correctly. Check the sensors. | Partly | Yes |
| S.315 | Compressor circuit breaker open | Partly | Yes |
| S.316 | WHB support active | No | Yes |
| S.350 | Immersion heater: Safety cut-out open | Partly | Yes |
| S.351 | Immersion heater: Flow temp. too high The flow temperature at the immersion heater is too high. Flow temperature > 75 °C. The heat pump is switched off. | Partly | Yes |
| S.352 | Immersion heater: Pressure too low | Partly | Yes |
| S.353 | Immersion heater: Flow rate too low | Partly | Yes |
| S.354 | Immersion heater: Phase failure | Partly | Yes |
| S.516 | De-icing mode active The heat pump de-ices the outdoor unit's heat exchanger. The heating mode is interrupted. The maximum de-icing time is 16 minutes. | No | Yes |
| S.575 | Frequency converter: Internal fault An internal electronics fault is present on the outdoor unit's inverter PCB. If this occurs three times, fault message F.752 appears. | Partly | Yes |
| S.581 | Connection fault: Frequency converter not recognised Missing communication between the frequency converter and the outdoor unit's PCB. After this occurs three times, fault message F.753 appears. | Partly | Yes |
| S.590 | Fault: 4-port valve position not correct The 4-port diverter valve does not move fully to the heating or cooling position. | Partly | Yes |
| SENSONET-LED-RED | Internet connection was disconnected; when connected via LAN: no Internet connection available | No | Yes |
| VRC700-ADDITIONAL-MODULE-FAULT | Additional module fault | Partly | Yes |
| VRC700-CASCADES-NOT-SUPPORTED | Cascades not supported | Partly | Yes |
| VRC700-COMMUNICATION-FAULT-HEAT-GENERATOR-N | Communication fault: Heat generator % | Partly | Yes |
| VRC700-COMMUNICATION-FAULT-HEAT-PUMP-N | Communication fault: Heat pump % | Partly | Yes |
| VRC700-COMMUNICATION-FAULT-VMS | Communication fault: VMS | Partly | Yes |
| VRC700-COMMUNICATION-FAULT-VPM-S | Communication fault: VPM-S | Partly | Yes |
| VRC700-COMMUNICATION-FAULT-VPM-W | Communication fault: VPM-W | Partly | Yes |
| VRC700-COMMUNICATION-FAULT-VR70-N | Communication fault: VR70 % | Partly | Yes |
| VRC700-COMMUNICATION-FAULT-VR71 | Communication fault: VR71 | Partly | Yes |
| VRC700-COMMUNICATION-FAULT-VR91-N | Communication fault: VR91 % | Partly | Yes |
| VRC700-FAULT-HEAT-GENERATOR-N | Fault: Heat generator % | Partly | Yes |
| VRC700-FAULT-HEAT-PUMP-N | Fault: Heat pump % | Partly | Yes |
| VRC700-FAULT-SOLAR-PUMP-N | Fault: Solar pump % | Partly | Yes |
| VRC700-HOT-WATER-TEMPERATURE-SENSOR-S1-NOT-CONNECTED | Hot water temperature sensor S1 not connected | Partly | Yes |
| VRC700-INCORRECT-CONFIGURATION-MA2-VWZ-AI | Incorrect configuration: MA2 VWZ-AI | Partly | Yes |
| VRC700-INCORRECT-CONFIGURATION-VR70 | Incorrect configuration: VR70 | Partly | Yes |
| VRC700-INCORRECT-CONFIGURATION-VR70-N-MA | Incorrect configuration: VR70 % MA | Partly | Yes |
| VRC700-INCORRECT-CONFIGURATION-VR71 | Incorrect configuration: VR71 | Partly | Yes |
| VRC700-INCORRECT-CONFIGURATION-VR71-MA | Incorrect configuration: VR71 MA | Partly | Yes |
| VRC700-MAINT-1 | The heat pump requires maintenance work (can be heat pump 1-7) | No | Yes |
| VRC700-MAINT-2 | The heat generator requires maintenance work (1-7) | No | Yes |
| VRC700-MAINT-3 | The ventilation unit requires maintenance work | No | Yes |
| VRC700-MAINT-4 | The water pressure is too low in the heating installation | No | Yes |
| VRC700-MAINT-5 | Date on which maintenance is due for the heating installation | No | Yes |
| VRC700-MODULE-NOT-SUPPORTED | Module not supported | Partly | Yes |
| VRC700-NO-ADDITIONAL-MODULE-CONNECTION | No additional module connection | Partly | Yes |
| VRC700-NO-REMOTE-CONTROL-FOR-HEATING-CIRCUIT-N | No remote control for heating circuit % | Partly | Yes |
| VRC700-NO-VR70-FOR-THIS-SYSTEM | No VR70 for this system | Partly | Yes |
| VRC700-PLUG-IN-ERROR | Plug-in error | Partly | Yes |
| VRC700-ROOM-TEMP-SENSOR-FAULT | Room temp. sensor fault | Partly | Yes |
| VRC700-SENSOR-FAULT-S-X-VR70-N | Sensor fault S $ VR70 % | Partly | Yes |
| VRC700-SENSOR-FAULT-S-X-VR71 | Sensor fault S $ VR71 | Partly | Yes |
| VRC700-SYSTEM-DIAGRAM-SELECTION-INCORRECT | System diagram selection incorrect | Partly | Yes |
| VRC700-VENTILATION-UNIT-CONNECTION | Ventilation unit connection | Partly | Yes |
| VRC700-VENTILATION-UNIT-FAULT | Ventilation unit fault | Partly | Yes |
| VRC700-VR71-NOT-SUPPORTED-FOR-THIS-SYSTEM | VR71 not supported for this system | Partly | Yes |