July 5, 2022
Vaillant boiler error codes
If you’re currently experiencing problems with your boiler, or a fault code has appeared on your boiler’s control panel, we’re here to help you find out what the error code means.
You can click the links below to find your boiler model.
Vaillant combination boiler error codes
- Vaillant ecoTec Pro combi boiler error codes
- Vaillant ecoTec Plus combi boiler error codes
- Vaillant ecoFit Pure combi boiler error codes
- Vaillant ecoTec exclusive Green iQ combi boiler error codes
- Vaillant ecoTec Plus Combination Store boiler error codes
Vaillant system boilers
- Vaillant ecoFit Pure system boiler error codes
- Vaillant ecoTec Plus system boiler error codes
- Vaillant ecoTec exclusive Green iQ system boiler error codes
- Vaillant ecoTec Plus 48 and 64kW system boiler error codes
- Vaillant ecoTec 46 and 65kW system boiler error codes
Vaillant regular boilers
Vaillant combination boiler error codes
Vaillant ecoTec Pro combi boiler error codes
Listed below are the most common fault codes that you might see if you have a Vaillant ecoTec Pro boiler installed:
| Message | Possible cause |
|---|---|
| F.00 Interruption: Flow sensor | Flow temperature sensor defective or not connected |
| F.01 Interruption: Return sensor | Return temperature sensor defective or not connected |
| F.10 Short circuit: Flow sensor | Flow temperature sensor defective or has short-circuited |
| F.11 Short circuit: Return sensor | Return temperature sensor defective or has short-circuited |
| F.20 Safety switch-off: Temperature limiter | Maximum temperature at the flow/return temperature sensor is too high when the safety cut out function is operating using the NTC |
| F.22 Safety switch-off: Low water pressure | No/insufficient water in the product or the water pressure is too low |
| F.23 Safety switch-off: Temp. spread too large | Temperature spread too great. Water circulation too low |
| F.24 Safety switch-off: Temp. incr. too fast | Temperature increase too fast |
| F.25 Safety switch-off: Flue temp. too high | Flue gas temperature too high |
| F.26 Fault: Fuel valve not working | Gas valve assembly stepper motor defective or not connected |
| F.27 Safety switch-off: Flame simulation | Monitoring electrode reports an incorrect flame |
| F.28 Start-up failure: Ignit. unsuccessful | Failure during start-up or ignition unsuccessful. Gas pressure monitor or thermal cut-out has been triggered. |
| F.29 Operating failure: Ignit. unsuccessful | Gas supply interrupted intermittently. Re-ignition failed. |
| F.32 Fault: Fan | Fan defective or not connected |
| F.49 Fault: eBUS | Undervoltage on the eBUS |
| F.61 Fault: Fuel valve actuation | The gas valve assembly cannot be actuated |
| F.62 Fault: Fuel valve switch off delay | Delayed switch-off sequence for the gas valve after the flame is extinguished |
| F.63 Fault: EPROM | EEPROM faulty |
| F.64 Fault: Electronics/sensor | Electronics, safety-relevant sensor or cable defective |
| F.65 Fault: Electronics temp. | Electronics defective or too hot due to external influences |
| F.67 Fault: Electronics/flame | Implausible flame signal |
| F.68 Fault: Flame signal un stable | Flame monitor reports an un stable flame signal |
| F.70 Fault: Invalid Device Specific Number | Incorrect/missing Device Specific Number or incorrect/missing coding resistor |
| F.71 Fault: Flow sensor | Flow temperature sensor re turns implausible values |
| F.72 Fault: Flow/return sensor | Temperature difference between flow and return temperature sensor is too great |
| F.73 Fault: Water press. sensor (signal too weak) | Water pressure sensor reports that the water pressure is too low |
| F.74 Fault: Water press. sensor (signal too strong) | Water pressure too high |
| F.75 Fault: Pump/ water shortage | Insufficient pressure jump de tected when starting the pump |
| F.77 Fault: Flue non-ret. valve/condens. pump | No flue non-return flap feed back; condensate pump over flow |
| F.78 Interrupt.: DHW outlet sensor on ext. contr. | UK link box is connected without the domestic hot water temperature sensor being bridged |
| F.83 Fault: NTC temp. gradient | Temperature difference between flow and return temperature sensor is too small |
| F.84 Fault: NTC temp. diff. implausible | Temperature difference is im plausible |
| F.85 Fault: NTCs fitted incorrectly | Flow/return temperature sensors returning incorrect/implausible values |
| Communication fault | Communication fault between the display and the PCB in the electronics box |
Vaillant ecoTec Plus combi boiler error codes
Listed below are the most common fault codes that you might see if you have a Vaillant ecoTec Plus boiler installed:
| Message | Possible cause |
|---|---|
| F.00 Interruption: Flow sensor | Flow temperature sensor de- fective or not connected |
| F.01 Interruption: Return sensor | Return temperature sensor de- fective or not connected |
| F.02 Interruption: DHW outlet sensor | Cylinder temperature sensor for the shift-load cylinder defective or not connected |
| F.03 Interruption: Cylinder sensor | Temperature sensor for the shift-load cylinder defective or not connected |
| F.10 Short circuit: Flow sensor | Flow temperature sensor de- fective or has short-circuited |
| F.11 Short circuit: Return sensor | Return temperature sensor de- fective or has short-circuited |
| F.12 Short circuit: DHW outlet sensor | Cylinder temperature sensor defective or has short-circuited |
| F.13 Short circuit: Cylinder sensor | Warm start sensor/cylinder tem- perature sensor defective or not connected |
| F.20 Safety switch-off: Tem- perature limiter | Maximum temperature at the flow/return temperature sensor is too high when the safety cut- out function is operating using the NTC |
| F.22 Safety switch-off: Low water pressure | No/insufficient water in the product or the water pressure is too low |
| F.23 Safety switch-off: Temp.spread too large | Temperature spread too great. Water circulation too low |
| F.24 Safety switch-off: Temp. incr. too fast | Temperature increase too fast |
| F.25 Safety switch-off: Flue temp. too high | flue gas temperature too high |
| F.26 Fault: Fuel valve not working | Gas valve assembly stepper motor defective or not connec- ted |
| F.27 Safety switch-off: Flame simulation | Monitoring electrode reports an incorrect flame |
| F.28 Start-up failure: Ignit. unsuccessful | Failure during start-up or igni- tion unsuccessful. Gas pressure monitor or thermal cut-out has been triggered. |
| F.29 Operating failure: Ignit. unsuccessful | Gas supply interrupted intermit- tently. Re-ignition failed. |
| F.32 Fault: Fan | Fan defective or not connected |
| F.42 Fault: Coding resistor | Coding resistor or gas group resistor causes a short circuit |
| F.49 Fault: eBUS | Undervoltage on the eBUS |
| F.52 Mass flow sensor not connected | Mass flow sensor defective or not connected |
| F.53 Fault: Mass flow sensor | Mass flow sensor defective |
| F.54 Fault: Boiler start | No gas inlet pressure or insuffi- cient gas inlet pressure causes faults when the product is star- ted |
| F.55 Fault: CO sensor | All-gas sensor defective or has short-circuited |
| F.56 Safety switch-off: CO limit exceeded | Safety shutdown after the CO limit value is exceeded |
| F.57 Fault: Measuring pro- gram | Regulation fault caused by cor- roded ignition electrode |
| F.61 Fault: Fuel valve actu- ation | The gas valve assembly cannot be actuated |
| F.62 Fault: Fuel valve switch- off delay | Delayed switch-off sequence for the gas valve after the flame is extinguished |
| F.63 Fault: EEPROM | EEPROM faulty |
| F.64 Fault: Electronics/sensor | Electronics, safety-relevant sensor or cable defective |
| F.65 Fault: Electronics temp. | Electronics defective or too hot due to external influences |
| F.67 Fault: Electronics/flame | Implausible flame signal |
| F.68 Fault: Flame signal un- stable | Flame monitor reports an un- stable flame signal |
| F.70 Fault: Invalid Device Specific Number | Incorrect/missing Device Specific Number or incorrect/missing coding resistor |
| F.71 Fault: Flow sensor | Flow temperature sensor re- turns implausible values |
| F.72 Fault: Flow/return sensor | Temperature difference between flow and return temperature sensor is too great |
| F.73 Fault: Water press. sensor (signal too weak) | Water pressure sensor reports that the water pressure is too low |
| F.74 Fault: Water press. sensor (signal too strong) | Water pressure too high |
| F.75 Fault: Pump/ water shortage | Insufficient pressure jump de- tected when starting the pump |
| F.77 Fault: Flue non-ret. valve/condens. pump | No flue non-return flap feed- back; condensate pump over- flow |
| F.78 Interrupt.: DHW outlet sensor on ext. contr. | UK link box is connected without the domestic hot water temperature sensor being bridged |
| F.80 Fault: actoSTOR inlet sensor | Inlet temperature sensor defect- ive or not connected |
| F.81 Fault: cylinder charging pump | Cylinder is not fully charged after specified time |
| F.82 Fault: Ext. current anode | External current anode defect- ive or not connected |
| F.83 Fault: NTC temp. gradi- ent | Temperature difference between flow and return temperature sensor is too small |
| F.84 Fault: NTC temp. diff. implausible | Temperature difference is im- plausible |
| F.85 Fault: NTCs fitted incor- rectly | Flow/return temperat- ure sensors returning incorrect/implausible values |
| F.90 Fault: Communication | Communication with actoSTOR interrupted |
| F.91 Fault: actoSTOR sensor | Sensor on the actoSTOR is defective |
| F.92 Fault: Incorrect gas type | The coding resistor on the PCB does not match the gas group that is entered |
| F.93 Fault: Check gas route | Combustion quality outside the permitted range |
| F.94 Fault: Vortex and differen- tial pressure | Sensors return implausible val- ues. |
| LED actoSTOR Modul actoSTOR communication status | actoSTOR communication status: Not connected, Con- nection error, Connection active |
| Communication fault | Communication fault between the display and the PCB in the electronics box |
Vaillant ecoFit Pure combi boiler error codes
Listed below are the most common fault codes that you might see if you have a Vaillant ecoFit Pure boiler installed:
| Fault code | Meaning |
|---|---|
| F.00 | Fault: Flow temperature sensor |
| F.01 | Fault: Return temperature sensor |
| F.10 | Short circuit: Flow temperature sensor |
| F.11 | Short circuit: Return temperature sensor |
| F.12 and F.91 | Short circuit: Cylinder temperature sensor |
| F.13 | Short circuit: Domestic hot water cylinder temperature sensor |
| F.20 | Safety switch-off: Overheating temperat- ure reached |
| F.22 | Safety switch-off: Low water pressure in the boiler |
| F.23 | Safety switch-off: Temperature difference too great (NTC1/NTC2) |
| F.24 | Safety switch-off: Temperature rise too fast |
| F.25 | Safety switch-off: Flue gas temperature too high |
| F.27 | Safety switch-off: Fault in flame detection |
| F.28 | Fault: Ignition unsuccessful when starting up |
| F.29 | Fault: Flame loss |
| F.32 | Fan frost protection function active: Fan speed outside the tolerance values |
| F.49 | eBUS fault: Voltage too low |
| F.61 | Fault: Gas valve control system |
| F.62 | Fault: Gas valve switch-off control |
| F.63 | Fault: EEPROM |
| F.64 | Fault: Electronics/sensor/analogue-to- digital converter |
| F.65 | Fault: Electronics temperature too high |
| F.67 | Value sent back by ASIC is incorrect (flame signal) |
| F.68 | Fault: Unstable flame (analogue input) |
| F.70 | Invalid product code (DSN) |
| F.71 | Fault: Flow/return temperature sensor |
| F.72 | Fault: Deviation in the water pressure sensor/return temperature sensor |
| F.73 | Fault: Water pressure sensor not con- nected or has short-circuited |
| F.74 | Fault: Electrical problem in the water pressure sensor |
| F.75 | Fault: Pressure sensor |
| F.76 | The safety cut-out in the primary heat exchanger is defective |
| F.77 | Fault: Condensate or smoke |
| F.78 | Interruption to DHW outlet sensor at external controller |
| F.83 | Fault: Dry fire |
| F.84 | Fault: Flow/return temperature sensor |
| F.85 | Fault: Temperature sensor |
| F.86 | Fault: Underfloor heating contact |
| F.87 | Fault: Electrodes |
| F.88 | Fault: Gas valve |
| F.89 | Fault: Pump |
| Connection | No communication between the PCB and the user interface |
Vaillant ecoTec exclusive Green iQ combi boiler error codes
Listed below are the most common fault codes that you might see if you have a Vaillant ecoTec exclusive Green iQ boiler installed:
| Code | Meaning |
|---|---|
| F.00 | Interruption: Flow sensor |
| F.01 | Interruption: Return sensor |
| F.02 | Interruption: DHW outlet sensor |
| F.03 | Interruption: Cylinder sensor |
| F.10 | Short circuit: Flow sensor |
| F.11 | Short circuit: Return sensor |
| F.12 | Short circuit: DHW outlet sensor |
| F.13 | Short circuit: Cylinder sensor |
| F.20 | Safety switch-off: Temperature limiter |
| F.22 | Safety switch-off: Low water pressure |
| F.23 | Safety switch-off: Temp.spread too large |
| F.24 | Safety switch-off: Temp. incr. too fast |
| F.25 | Safety switch-off: Flue temp. too high |
| F.26 | Fault: Fuel valve not working |
| F.27 | Safety switch-off: Flame simulation |
| F.28 | Start-up failure: Ignit. unsuccessful |
| F.29 | Start-up failure: Ignit. unsuccessful |
| F.32 | Fault: Fan |
| F.33 | Pressure switch |
| F.35 | Fault: Air/flue gas duct |
| F.42 | Fault: Coding resistor |
| F.49 | Fault: eBUS |
| F.55 | Fault: CO sensor |
| F.56 | Safety switch-off: CO limit exceeded |
| F.57 | Fault: Measuring program |
| F.61 | Fault: Fuel valve actuation |
| F.62 | Fault: Fuel valve switch-off delay |
| F.63 | Fault: EEPROM |
| F.64 | Fault: Electronics/sensor |
| F.65 | Fault: Electronics temp. |
| F.67 | Fault: Electronics/flame |
| F.68 | Fault: Flame signal unstable |
| F.70 | Fault: Invalid Device Specific Number |
| F.71 | Fault: Flow sensor |
| F.72 | Fault: Flow/return sensor |
| F.73 | Fault: Water press. sensor |
| F.74 | Fault: Water press. sensor |
| F.75 | Fault: Pump/ water shortage |
| F.77 | Fault: Flue non-ret. valve/condens. pump |
| F.78 | Interrupt.: DHW outlet sensor on ext. contr. |
| F.80 | Fault: actoSTOR inlet sensor |
| F.81 | Fault: cylinder charging pump |
| F.82 | Fault: Ext. current anode |
| F.83 | Fault: NTC temp. gradient |
| F.84 | Fault: NTC temp. diff. implausible |
| F.85 | Fault: NTCs fitted incorrectly |
| F.90 | Fault: Communication |
| F.94 | Fault: Vortex and differential pressure |
| LED actoSTOR module | actoSTOR electronics status |
| Communication fault | Communication fault |
Vaillant ecoTec Plus Combination Store boiler error codes
Listed below are the most common fault codes that you might see if you have a Vaillant ecoTec Plus Combination Store boiler installed:
| Code | Meaning |
|---|---|
| F.00 | Flow temperature sensor interruption |
| F.01 | Return temperature sensor interruption |
| F.02 | Interruption cylinder charging sensor actoSTOR (NTC) only in combination with F.91 |
| F.03 | Interruption cylinder sensor actoSTOR (NTC) only in combination with F.91 |
| F.10 | Flow NTC short circuit |
| F.11 | Return NTC short circuit |
| F.12 | Short circuit at cylinder charging sensor (NTC) only in combination with F.91 |
| F.13 | Product with integrated hot water generation: Short circuit warm start sensor/cylinder sensor Product with integrated hot water generation and actoSTOR: Short circuit cylinder sensor (NTC) only in combination with F.91 |
| F.20 | Safety switch-off: Temperature limiter |
| F.22 | Safety switch-off: Low water pressure |
| F.23 | Safety switch-off: Temperature difference too great |
| F.24 | Safety switch-off: Temperature rise too fast |
| F.25 | Safety switch-off: Flue gas temperature too high |
| F.26 | Fault: Gas valve without function |
| F.27 | Safety switch-off: Flame simulation |
| F.28 | Failure during start-up: Ignition unsuccess- ful |
| F.29 | Failure during operation: Re-ignition unsuc- cessful |
| F.32 | Fan fault |
| F.42 | Coding resistance fault (possible in combin- ation with F.70) |
| F.49 | Fault: eBUS |
| F.52 | Contact fault mass flow sensor/Venturi |
| F.53 | Combustion regulation fault |
| F.54 | Fault in the gas supply (in combination with F.28/F.29) |
| F.56 | Combustion component fault |
| F.57 | End comfort protection mode |
| F.61 | Gas valve actuation fault |
| F.62 | Gas valve switch-off delay |
| F.63 | Fault: EEPROM |
| F.64 | Fault: Electronics/NTC |
| F.65 | Fault: Electronics temp. |
| F.67 | Fault: Electronics/flame |
| F.68 | Fault: Unstable flame signal |
| F.70 | Invalid device specific number (DSN) |
| F.71 | Flow NTC fault |
| F.72 | Flow/return NTC fault |
| F.73 | Water pressure sensor signal in the wrong range (too low) |
| F.74 | Water pressure sensor signal outside cor- rect range (too high) |
| F.75 | Fault: No pressure change detection when starting pump |
| F.77 | Fault: Flue non-return flap/condensate pump |
| F.78 | Interruption to DHW outlet sensor at the external controller |
| F.80 | Interruption or short circuit of secondary heat exchanger inlet sensor; only in connection with F.91 |
| F.81 | actoSTOR charging pump defective; only in combination with F.91 |
| F.83 | Fault: Flow and/or return temperature sensor temperature change |
| F.84 | Fault: Flow/return temperature sensor tem- perature difference implausible |
| F.85 | Fault: Flow and return temperature sensors incorrectly installed |
| F.90 | Communication with actoSTOR module interrupted |
| F.91 | Sensor/actuator fault on actoSTOR module |
| F.92 | Coding resistance fault |
| F.93 | Poor combustion quality |
| LED actoSTOR module | actoSTOR electronics status |
| Communication fault | No communication with the PCB |
Vaillant system boiler error codes
Vaillant ecoFit Pure system boiler error codes
Listed below are the most common fault codes that you might see if you have a Vaillant ecoFit Pure System boiler installed:
| Fault code | Meaning |
|---|---|
| F.00 | Fault: Flow temperature sensor |
| F.01 | Fault: Return temperature sensor |
| F.10 | Short circuit: Flow temperature sensor |
| F.11 | Short circuit: Return temperature sensor |
| F.12 and F.91 | Short circuit: Cylinder temperature sensor |
| F.13 | Short circuit: Domestic hot water cylinder temperature sensor |
| F.20 | Safety switch-off: Overheating temperat- ure reached |
| F.22 | Safety switch-off: Low water pressure in the boiler |
| F.23 | Safety switch-off: Temperature difference too great (NTC1/NTC2) |
| F.24 | Safety switch-off: Temperature rise too fast |
| F.25 | Safety switch-off: Flue gas temperature too high |
| F.27 | Safety switch-off: Fault in flame detection |
| F.28 | Fault: Ignition unsuccessful when starting up |
| F.29 | Fault: Flame loss |
| F.32 | Fan frost protection function active: Fan speed outside the tolerance values |
| F.49 | eBUS fault: Voltage too low |
| F.61 | Fault: Gas valve control system |
| F.62 | Fault: Gas valve switch-off control |
| F.63 | Fault: EEPROM |
| F.64 | Fault: Electronics/sensor/analogue-to- digital converter |
| F.65 | Fault: Electronics temperature too high |
| F.67 | Value sent back by ASIC is incorrect (flame signal) |
| F.68 | Fault: Unstable flame (analogue input) |
| F.70 | Invalid product code (DSN) |
| F.71 | Fault: Flow/return temperature sensor |
| F.72 | Fault: Deviation in the water pressure sensor/return temperature sensor |
| F.73 | Fault: Water pressure sensor not con- nected or has short-circuited |
| F.74 | Fault: Electrical problem in the water pressure sensor |
| F.75 | Fault: Pressure sensor |
| F.76 | The safety cut-out in the primary heat exchanger is defective |
| F.77 | Fault: Condensate or smoke |
| F.78 | Interruption to DHW outlet sensor at external controller |
| F.83 | Fault: Dry fire |
| F.84 | Fault: Flow/return temperature sensor |
| F.85 | Fault: Temperature sensor |
| F.86 | Fault: Underfloor heating contact |
| F.87 | Fault: Electrodes |
| F.88 | Fault: Gas valve |
| F.89 | Fault: Pump |
| Connection | No communication between the PCB and the user interface |
Vaillant ecoTec Plus system boiler error codes
Listed below are the most common fault codes that you might see if you have a Vaillant ecoTec Plus system boiler installed:
| Message | Possible cause |
|---|---|
| F.00 Interruption: Flow sensor | Flow temperature sensor de- fective or not connected |
| F.01 Interruption: Return sensor | Return temperature sensor de- fective or not connected |
| F.02 Interruption: DHW outlet sensor | Cylinder temperature sensor for the shift-load cylinder defective or not connected |
| F.03 Interruption: Cylinder sensor | Temperature sensor for the shift-load cylinder defective or not connected |
| F.10 Short circuit: Flow sensor | Flow temperature sensor de- fective or has short-circuited |
| F.11 Short circuit: Return sensor | Return temperature sensor de- fective or has short-circuited |
| F.12 Short circuit: DHW outlet sensor | Cylinder temperature sensor defective or has short-circuited |
| F.13 Short circuit: Cylinder sensor | Warm start sensor/cylinder tem- perature sensor defective or not connected |
| F.20 Safety switch-off: Tem- perature limiter | Maximum temperature at the flow/return temperature sensor is too high when the safety cut- out function is operating using the NTC |
| F.22 Safety switch-off: Low water pressure | No/insufficient water in the product or the water pressure is too low |
| F.23 Safety switch-off: Temp.spread too large | Temperature spread too great. Water circulation too low |
| F.24 Safety switch-off: Temp. incr. too fast | Temperature increase too fast |
| F.25 Safety switch-off: Flue temp. too high | flue gas temperature too high |
| F.26 Fault: Fuel valve not working | Gas valve assembly stepper motor defective or not connec- ted |
| F.27 Safety switch-off: Flame simulation | Monitoring electrode reports an incorrect flame |
| F.28 Start-up failure: Ignit. unsuccessful | Failure during start-up or igni- tion unsuccessful. Gas pressure monitor or thermal cut-out has been triggered. |
| F.29 Operating failure: Ignit. unsuccessful | Gas supply interrupted intermit- tently. Re-ignition failed. |
| F.32 Fault: Fan | Fan defective or not connected |
| F.42 Fault: Coding resistor | Coding resistor or gas group resistor causes a short circuit |
| F.49 Fault: eBUS | Undervoltage on the eBUS |
| F.52 Mass flow sensor not connected | Mass flow sensor defective or not connected |
| F.53 Fault: Mass flow sensor | Mass flow sensor defective |
| F.54 Fault: Boiler start | No gas inlet pressure or insuffi- cient gas inlet pressure causes faults when the product is star- ted |
| F.55 Fault: CO sensor | All-gas sensor defective or has short-circuited |
| F.56 Safety switch-off: CO limit exceeded | Safety shutdown after the CO limit value is exceeded |
| F.57 Fault: Measuring pro- gram | Regulation fault caused by cor- roded ignition electrode |
| F.61 Fault: Fuel valve actu- ation | The gas valve assembly cannot be actuated |
| F.62 Fault: Fuel valve switch- off delay | Delayed switch-off sequence for the gas valve after the flame is extinguished |
| F.63 Fault: EEPROM | EEPROM faulty |
| F.64 Fault: Electronics/sensor | Electronics, safety-relevant sensor or cable defective |
| F.65 Fault: Electronics temp. | Electronics defective or too hot due to external influences |
| F.67 Fault: Electronics/flame | Implausible flame signal |
| F.68 Fault: Flame signal un- stable | Flame monitor reports an un- stable flame signal |
| F.70 Fault: Invalid Device Specific Number | Incorrect/missing Device Specific Number or incorrect/missing coding resistor |
| F.71 Fault: Flow sensor | Flow temperature sensor re- turns implausible values |
| F.72 Fault: Flow/return sensor | Temperature difference between flow and return temperature sensor is too great |
| F.73 Fault: Water press. sensor (signal too weak) | Water pressure sensor reports that the water pressure is too low |
| F.74 Fault: Water press. sensor (signal too strong) | Water pressure too high |
| F.75 Fault: Pump/ water shortage | Insufficient pressure jump de- tected when starting the pump |
| F.77 Fault: Flue non-ret. valve/condens. pump | No flue non-return flap feed- back; condensate pump over- flow |
| F.78 Interrupt.: DHW outlet sensor on ext. contr. | UK link box is connected without the domestic hot water temperature sensor being bridged |
| F.80 Fault: actoSTOR inlet sensor | Inlet temperature sensor defect- ive or not connected |
| F.81 Fault: cylinder charging pump | Cylinder is not fully charged after specified time |
| F.82 Fault: Ext. current anode | External current anode defect- ive or not connected |
| F.83 Fault: NTC temp. gradi- ent | Temperature difference between flow and return temperature sensor is too small |
| F.84 Fault: NTC temp. diff. implausible | Temperature difference is im- plausible |
| F.85 Fault: NTCs fitted incor- rectly | Flow/return temperat- ure sensors returning incorrect/implausible values |
| F.90 Fault: Communication | Communication with actoSTOR interrupted |
| F.91 Fault: actoSTOR sensor | Sensor on the actoSTOR is defective |
| F.92 Fault: Incorrect gas type | The coding resistor on the PCB does not match the gas group that is entered |
| F.93 Fault: Check gas route | Combustion quality outside the permitted range |
| F.94 Fault: Vortex and differen- tial pressure | Sensors return implausible val- ues. |
| LED actoSTOR Modul actoSTOR communication status | actoSTOR communication status: Not connected, Con- nection error, Connection active |
| Communication fault | Communication fault between the display and the PCB in the electronics box |
Vaillant ecoTec exclusive Green iQ system boiler error codes
Listed below are the most common fault codes that you might see if you have a Vaillant ecoTec exclusive Green iQ system boiler installed:
| Code | Meaning |
|---|---|
| F.00 | Interruption: Flow sensor |
| F.01 | Interruption: Return sensor |
| F.02 | Interruption: DHW outlet sensor |
| F.03 | Interruption: Cylinder sensor |
| F.10 | Short circuit: Flow sensor |
| F.11 | Short circuit: Return sensor |
| F.12 | Short circuit: DHW outlet sensor |
| F.13 | Short circuit: Cylinder sensor |
| F.20 | Safety switch-off: Temperature limiter |
| F.22 | Safety switch-off: Low water pressure |
| F.23 | Safety switch-off: Temp.spread too large |
| F.24 | Safety switch-off: Temp. incr. too fast |
| F.25 | Safety switch-off: Flue temp. too high |
| F.26 | Fault: Fuel valve not working |
| F.27 | Safety switch-off: Flame simulation |
| F.28 | Start-up failure: Ignit. unsuccessful |
| F.29 | Start-up failure: Ignit. unsuccessful |
| F.32 | Fault: Fan |
| F.33 | Pressure switch |
| F.35 | Fault: Air/flue gas duct |
| F.42 | Fault: Coding resistor |
| F.49 | Fault: eBUS |
| F.55 | Fault: CO sensor |
| F.56 | Safety switch-off: CO limit exceeded |
| F.57 | Fault: Measuring program |
| F.61 | Fault: Fuel valve actuation |
| F.62 | Fault: Fuel valve switch-off delay |
| F.63 | Fault: EEPROM |
| F.64 | Fault: Electronics/sensor |
| F.65 | Fault: Electronics temp. |
| F.67 | Fault: Electronics/flame |
| F.68 | Fault: Flame signal unstable |
| F.70 | Fault: Invalid Device Specific Number |
| F.71 | Fault: Flow sensor |
| F.72 | Fault: Flow/return sensor |
| F.73 | Fault: Water press. sensor |
| F.74 | Fault: Water press. sensor |
| F.75 | Fault: Pump/ water shortage |
| F.77 | Fault: Flue non-ret. valve/condens. pump |
| F.78 | Interrupt.: DHW outlet sensor on ext. contr. |
| F.80 | Fault: actoSTOR inlet sensor |
| F.81 | Fault: cylinder charging pump |
| F.82 | Fault: Ext. current anode |
| F.83 | Fault: NTC temp. gradient |
| F.84 | Fault: NTC temp. diff. implausible |
| F.85 | Fault: NTCs fitted incorrectly |
| F.90 | Fault: Communication |
| F.94 | Fault: Vortex and differential pressure |
| LED actoSTOR module | actoSTOR electronics status |
| Communication fault | Communication fault |
Vaillant ecoTec Plus 48 and 64kW system boiler error codes
Listed below are the most common fault codes that you might see if you have a Vaillant ecoTec Plus 48kW or 64kW system boiler installed:
| Message | Possible cause |
|---|---|
| F.00 Flow temperature sensor interruption | NTC plug loose/not plugged in |
| NTC sensor defective | |
| Multiple plug loose/not plugged in | |
| Interruption in the cable harness | |
| F.01 Return temperature sensor interruption | NTC plug loose/not plugged in |
| NTC sensor defective | |
| Multiple plug loose/not plugged in | |
| Interruption in the cable harness | |
| F.03 Cylinder temperature sensor interruption | NTC sensor defective |
| NTC plug loose/not plugged in | |
| Connection to cylinder electron- ics defective | |
| F.10 Flow temperature sensor short circuit | NTC sensor defective |
| Short circuit in the cable har- ness | |
| F.11 Return temperature sensor short circuit | NTC sensor defective |
| Short circuit in the cable har- ness | |
| F.13 Cylinder temperature sensor short circuit | NTC sensor defective |
| Short circuit in the cable har- ness | |
| F.20 Safety shutdown: Safety cut-out | Flow NTC defective |
| Return NTC defective | |
| Earth connection faulty | |
| Stray spark via the ignition cable, ignition plug or ignition electrode | |
| F.22 Safety shutdown: Water deficiency | Insufficient/no water in the product. |
| Interruption in the cable harness | |
| F.23 Safety shutdown: Temper- ature spread too great | Pump blocked |
| Pump runs with insufficient out- put | |
| Flow and return NTC connected the wrong way round | |
| F.24 Safety shutdown: Temper- ature rise too fast | Pump blocked |
| Pump runs with insufficient out- put | |
| Non-return valve blocked | |
| Non-return valve installed incor- rectly | |
| System pressure too low | |
| F.25 Safety shutdown: Flue gas temperature too high | Flue gas safety cut-out plug is not plugged in or is loose |
| Interruption in the cable harness | |
| F.27 Safety shutdown: Flame simulation | Gas solenoid valve not leak- tight |
| Moisture on the PCB | |
| Flame monitor defective | |
| F.28 Ignition unsuccessful | Gas stopcock closed |
| Gas valve assembly defective | |
| The gas pressure monitor has been triggered | |
| Gas flow pressure too low | |
| The thermal isolator device has been triggered | |
| Cable connections not plugged in/loose | |
| Ignition system defective | |
| PCB defective | |
| Ionisation flow interrupted | |
| Earthing defective | |
| Air in the gas supply | |
| Gas meter defective | |
| Gas supply is interrupted | |
| Flue gas circulation is incorrect | |
| Ignition misfire | |
| Diagnostics code D.085 incor- rectly set | |
| Condensate siphon blocked | |
| F.29 Ignition and check faults during operation – flame has gone out | Gas valve assembly defective |
| Gas meter defective | |
| The gas pressure monitor has been triggered | |
| Air in the gas supply | |
| Gas flow pressure too low | |
| The thermal isolator device has been triggered | |
| Cable connections not plugged in/loose | |
| Ignition system defective | |
| Ionisation flow interrupted | |
| Earthing defective | |
| PCB defective | |
| F.32 Fan fault | Plug on fan not plugged in or is loose |
| Multiple plug loose/not plugged in | |
| Interruption in the cable harness | |
| Fan blocked | |
| Electronics defective | |
| F.33 Air pressure switch fault | Air/flue pipe blocked |
| Defective air pressure switch | |
| Cable connections not plugged in/loose | |
| Fan defective | |
| F.33 Air pressure switch fault | PCB defective |
| Excessive counter-pressure in the air/flue pipe | |
| F.49 Fault: eBUS | eBUS overload |
| Short circuit in the eBUS con- nection | |
| Different polarities at the eBUS connection | |
| F.61 Gas safety valve drive fault | Short circuit in the cable har- ness |
| Gas valve assembly defective | |
| PCB defective | |
| F.62 Gas safety valve connec- tion fault | PCB defective |
| The connection to the gas valve assembly has been interrup- ted/broken | |
| F.63 Fault: EEPROM | PCB defective |
| F.64 Fault: Electronics/NTC | Flow NTC short circuit. |
| Return NTC short circuit | |
| PCB defective | |
| F.65 Electronics temperature fault | Electronics overheated |
| PCB defective | |
| F.67 Flame plausibility fault | PCB defective |
| F.70 Invalid device specific number (DSN) | Device Specific Number not set/is incorrect |
| Output range coding resistor missing or is incorrect | |
| F.71 Flow temperature sensor fault | The flow NTC reports a con- stant value |
| Incorrect position of the flow NTC | |
| Flow NTC defective | |
| F.72 Flow and/or return temper- ature sensor fault | Flow NTC defective |
| Return NTC defective | |
| F.73 Water pressure sensor signal in the wrong range (too low) | Short circuit in the cable har- ness |
| Interruption in the cable harness | |
| Water pressure sensor defect- ive | |
| F.74 Water pressure sensor signal outside correct range (too high) | Short circuit in the cable har- ness |
| Interruption in the cable harness | |
| Water pressure sensor defect- ive | |
| F.75 Pump fault/water defi- ciency | Malfunction |
| D.149 = 1, pump blocked alarm | |
| D.149 = 2, electrical pump fault alarm | |
| D.149 = 3, pump dry running alarm | |
| F.75 Pump fault/water defi- ciency | D.149 = 5, no pressure peak detection |
| D.149 = 6, no feedback from the pump | |
| D.149 = 7, incorrect pump de- tected | |
| D.149 = 8, flow rate at the end of the purge programme is in- sufficient | |
| F.77 Accessory fault (flue non- return flap, condensate pump, etc.) | No feedback from the flue non- return flap or the feedback is incorrect |
| Flue non-return flap defective | |
| No feedback from the condens- ate pump or the feedback is in- correct | |
| F.83 Fault: Flow and/or return temperature sensor temperature change | Water deficiency |
| Flow NTC: No contact | |
| Return NTC: No contact | |
| F.84 Fault: Temperature differ- ence at the flow and return tem- perature sensors | Flow NTC installed incorrectly |
| Return NTC installed incorrectly | |
| F.85 Flow and return temperat- ure sensors have been installed incorrectly (inverted) | Flow/return NTC installed on the same/incorrect pipe |
Vaillant ecoTec 46 and 65kW system boiler error codes
Listed below are the most common fault codes that you might see if you have a Vaillant ecoTec Plus 48kW or 64kW system boiler installed:
| Code | Meaning |
|---|---|
| F. 0 | Flow temperature sensor interruption |
| F. 1 | Return temperature sensor interruption |
| F.10 | Flow NTC short circuit |
| F.11 | Return NTC short circuit |
| F.13 | Cylinder temperature sensor short circuit |
| F.20 | Safety switch-off: Temperature limiter |
| F.22 | Safety switch-off: Low water pressure |
| F.23 | Safety switch-off: Temperature difference too great |
| F.24 | Safety switch-off: Temperature rise too fast |
| F.27 | Safety switch-off: Flame simulation |
| F.28 | Failure during start-up: Ignition unsuccessful |
| F.29 | Failure during operation: Re-ignition unsuccess- ful |
| F.32 | Fan fault |
| F.49 | Fault: eBUS |
| F.61 | Gas valve actuation fault |
| F.62 | Gas valve switch-off delay |
| F.63 | Fault: EEPROM |
| F.64 | Fault: Electronics/NTC |
| F.65 | Fault: Electronics temp. |
| F.67 | Fault: Electronics/flame |
| F.70 | Invalid device specific number (DSN) |
| F.71 | Flow NTC fault |
| F.72 | Flow/return NTC fault |
| F.73 | Water pressure sensor signal in the wrong range (too low) |
| F.74 | Water pressure sensor signal outside correct range (too high) |
| F.75 | Fault: No pressure change detection when start- ing pump |
| F.77 | Fault: Flue non-return flap/condensate pump |
| con | No communication with the PCB |
Vaillant regular boiler error codes
Vaillant ecoTec Plus regular boiler error codes
Listed below are the most common fault codes that you might see if you have a Vaillant ecoTec Plus regular boiler installed:
| Fault code | Meaning |
|---|---|
| F.00 | Fault: Flow temperature sensor |
| F.01 | Fault: Return temperature sensor |
| F.10 | Short circuit: Flow temperature sensor |
| F.11 | Short circuit: Return temperature sensor |
| F.12 and F.91 | Short circuit: Cylinder temperature sensor |
| F.13 | Short circuit: Domestic hot water cylinder temperature sensor |
| F.20 | Safety switch-off: Overheating temperat- ure reached |
| F.23 | Safety switch-off: Temperature difference too great (NTC1/NTC2) |
| F.24 | Safety switch-off: Temperature rise too fast |
| F.25 | Safety switch-off: Flue gas temperature too high |
| F.27 | Safety switch-off: Fault in flame detection |
| F.28 | Fault: Ignition unsuccessful when starting up |
| F.29 | Fault: Flame loss |
| F.32 | Fan frost protection function active: Fan speed outside the tolerance values |
| F.49 | eBUS fault: Voltage too low |
| F.61 | Fault: Gas valve control system |
| F.62 | Fault: Gas valve switch-off control |
| F.63 | Fault: EEPROM |
| F.64 | Fault: Electronics/sensor/analogue-to- digital converter |
| F.65 | Fault: Electronics temperature too high |
| F.67 | Value sent back by ASIC is incorrect (flame signal) |
| F.68 | Fault: Unstable flame (analogue input) |
| F.70 | Invalid product code (DSN) |
| F.71 | Fault: Flow/return temperature sensor |
| F.72 | Fault: Deviation in the water pressure sensor/return temperature sensor |
| F.77 | Fault: Condensate or smoke |
| F.78 | Interruption to DHW outlet sensor at external controller |
| F.83 | Fault: Dry fire |
| F.84 | Fault: Flow/return temperature sensor |
| F.85 | Fault: Temperature sensor |
| F.86 | Fault: Underfloor heating contact |
| F.87 | Fault: Electrodes |
| F.88 | Fault: Gas valve |
| Connection | No communication between the PCB and the user interface |
Vaillant ecoFit Pure regular boiler error codes
Listed below are the most common fault codes that you might see if you have a Vaillant ecoFit Pure regular boiler installed:
| Code | Meaning |
|---|---|
| F.00 | Flow temperature sensor interruption |
| F.01 | Return temperature sensor interruption |
| F.10 | Flow NTC short circuit |
| F.11 | Return NTC short circuit |
| F.13 | Warm start sensor/cylinder sensor short circuit |
| F.22 | Safety switch-off: Low water pressure |
| F.23 | Safety switch-off: Temperature difference too great |
| F.24 | Safety switch-off: Temperature rise too fast |
| F.25 | Safety switch-off: Flue gas temperature too high |
| F.27 | Safety switch-off: Flame simulation |
| F.28 | Failure during start-up: Ignition unsuccessful |
| F.29 | Failure during operation: Re-ignition unsuccess- ful |
| F.32 | Fan fault |
| F.49 | Fault: eBUS |
| F.61 | Fault: Gas valve regulation |
| F.62 | Fault: Gas valve switch-off delay |
| F.63 | Fault: EEPROM |
| F.64 | Fault: Electronics/NTC |
| F.65 | Fault: Electronics temp. |
| F.67 | Fault: Electronics/flame |
| F.68 | Fault: Unstable flame signal |
| F.70 | Invalid device specific number (DSN) |
| F.71 | Flow NTC fault |
| F.72 | Flow/return NTC fault |
| F.73 | Water pressure sensor signal in the wrong range (too low) |
| F.74 | Water pressure sensor signal outside correct range (too high) |
| F.75 | Fault: No pressure change detection when start- ing pump |
| F.76 | Overheating protection on primary heat ex- changer has responded |
| F.77 | Fault: Flue non-return flap/condensate pump |
| F.83 | Fault: Flow and/or return temperature sensor temperature change |
| F.85 | Fault: Flow and return temperature sensors incorrectly installed |
| F.87 | Ignition transformer not connected |
| F.88 | Gas valve not connected |
| F.89 | Incorrect pump detected |
| con | No communication with the PCB |
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