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Vaillant boiler error codes

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:

MessagePossible cause
F.00 Interruption: Flow sensorFlow temperature sensor defective or not connected
F.01 Interruption: Return sensorReturn temperature sensor defective or not connected
F.10 Short circuit: Flow sensorFlow temperature sensor defective or has short-circuited
F.11 Short circuit: Return sensorReturn temperature sensor defective or has short-circuited
F.20 Safety switch-off: Temperature limiterMaximum 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 pressureNo/insufficient water in the product or the water pressure is too low
F.23 Safety switch-off: Temp. spread too largeTemperature spread too great. Water circulation too low
F.24 Safety switch-off: Temp. incr. too fastTemperature increase too fast
F.25 Safety switch-off: Flue temp. too highFlue gas temperature too high
F.26 Fault: Fuel valve not workingGas valve assembly stepper motor defective or not connected
F.27 Safety switch-off: Flame simulationMonitoring electrode reports an incorrect flame
F.28 Start-up failure: Ignit. unsuccessfulFailure during start-up or ignition unsuccessful. Gas pressure monitor or thermal cut-out has been triggered.
F.29 Operating failure: Ignit. unsuccessfulGas supply interrupted intermittently. Re-ignition failed.
F.32 Fault: FanFan defective or not connected
F.49 Fault: eBUSUndervoltage on the eBUS
F.61 Fault: Fuel valve actuationThe gas valve assembly cannot be actuated
F.62 Fault: Fuel valve switch off delayDelayed switch-off sequence for the gas valve after the flame is extinguished
F.63 Fault: EPROMEEPROM faulty
F.64 Fault: Electronics/sensorElectronics, safety-relevant sensor or cable defective
F.65 Fault: Electronics temp.Electronics defective or too hot due to external influences
F.67 Fault: Electronics/flameImplausible flame signal
F.68 Fault: Flame signal un stableFlame monitor reports an un stable flame signal
F.70 Fault: Invalid Device Specific NumberIncorrect/missing Device Specific Number or incorrect/missing coding resistor
F.71 Fault: Flow sensorFlow temperature sensor re turns implausible values
F.72 Fault: Flow/return sensorTemperature 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 shortageInsufficient pressure jump de tected when starting the pump
F.77 Fault: Flue non-ret. valve/condens. pumpNo 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. gradientTemperature difference between flow and return temperature sensor is too small
F.84 Fault: NTC temp. diff. implausibleTemperature difference is im plausible
F.85 Fault: NTCs fitted incorrectlyFlow/return temperature sensors returning incorrect/implausible values
Communication faultCommunication 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:

MessagePossible cause
F.00 Interruption: Flow sensorFlow temperature sensor de- fective or not connected
F.01 Interruption: Return sensorReturn temperature sensor de- fective or not connected
F.02 Interruption: DHW outlet sensorCylinder temperature sensor for the shift-load cylinder defective or not connected
F.03 Interruption: Cylinder sensorTemperature sensor for the shift-load cylinder defective or not connected
F.10 Short circuit: Flow sensorFlow temperature sensor de- fective or has short-circuited
F.11 Short circuit: Return sensorReturn temperature sensor de- fective or has short-circuited
F.12 Short circuit: DHW outlet sensorCylinder temperature sensor defective or has short-circuited
F.13 Short circuit: Cylinder sensorWarm start sensor/cylinder tem- perature sensor defective or not connected
F.20 Safety switch-off: Tem- perature limiterMaximum 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 pressureNo/insufficient water in the product or the water pressure is too low
F.23 Safety switch-off: Temp.spread too largeTemperature spread too great. Water circulation too low
F.24 Safety switch-off: Temp. incr. too fastTemperature increase too fast
F.25 Safety switch-off: Flue temp. too highflue gas temperature too high
F.26 Fault: Fuel valve not workingGas valve assembly stepper motor defective or not connec- ted
F.27 Safety switch-off: Flame simulationMonitoring electrode reports an incorrect flame
F.28 Start-up failure: Ignit. unsuccessfulFailure during start-up or igni- tion unsuccessful. Gas pressure monitor or thermal cut-out has been triggered.
F.29 Operating failure: Ignit. unsuccessfulGas supply interrupted intermit- tently. Re-ignition failed.
F.32 Fault: FanFan defective or not connected
F.42 Fault: Coding resistorCoding resistor or gas group resistor causes a short circuit
F.49 Fault: eBUSUndervoltage on the eBUS
F.52 Mass flow sensor not connectedMass flow sensor defective or not connected
F.53 Fault: Mass flow sensorMass flow sensor defective
F.54 Fault: Boiler startNo gas inlet pressure or insuffi- cient gas inlet pressure causes faults when the product is star- ted
F.55 Fault: CO sensorAll-gas sensor defective or has short-circuited
F.56 Safety switch-off: CO limit exceededSafety shutdown after the CO limit value is exceeded
F.57 Fault: Measuring pro- gramRegulation fault caused by cor- roded ignition electrode
F.61 Fault: Fuel valve actu- ationThe gas valve assembly cannot be actuated
F.62 Fault: Fuel valve switch- off delayDelayed switch-off sequence for the gas valve after the flame is extinguished
F.63 Fault: EEPROMEEPROM faulty
F.64 Fault: Electronics/sensorElectronics, safety-relevant sensor or cable defective
F.65 Fault: Electronics temp.Electronics defective or too hot due to external influences
F.67 Fault: Electronics/flameImplausible flame signal
F.68 Fault: Flame signal un- stableFlame monitor reports an un- stable flame signal
F.70 Fault: Invalid Device Specific NumberIncorrect/missing Device Specific Number or incorrect/missing coding resistor
F.71 Fault: Flow sensorFlow temperature sensor re- turns implausible values
F.72 Fault: Flow/return sensorTemperature 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 shortageInsufficient pressure jump de- tected when starting the pump
F.77 Fault: Flue non-ret. valve/condens. pumpNo 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 sensorInlet temperature sensor defect- ive or not connected
F.81 Fault: cylinder charging pumpCylinder is not fully charged after specified time
F.82 Fault: Ext. current anodeExternal current anode defect- ive or not connected
F.83 Fault: NTC temp. gradi- entTemperature difference between flow and return temperature sensor is too small
F.84 Fault: NTC temp. diff. implausibleTemperature difference is im- plausible
F.85 Fault: NTCs fitted incor- rectlyFlow/return temperat- ure sensors returning incorrect/implausible values
F.90 Fault: CommunicationCommunication with actoSTOR interrupted
F.91 Fault: actoSTOR sensorSensor on the actoSTOR is defective
F.92 Fault: Incorrect gas typeThe coding resistor on the PCB does not match the gas group that is entered
F.93 Fault: Check gas routeCombustion quality outside the permitted range
F.94 Fault: Vortex and differen- tial pressureSensors return implausible val- ues.
LED actoSTOR Modul actoSTOR communication statusactoSTOR communication status: Not connected, Con- nection error, Connection active
Communication faultCommunication 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 codeMeaning
F.00Fault: Flow temperature sensor
F.01Fault: Return temperature sensor
F.10Short circuit: Flow temperature sensor
F.11Short circuit: Return temperature sensor
F.12 and F.91Short circuit: Cylinder temperature sensor
F.13Short circuit: Domestic hot water cylinder temperature sensor
F.20Safety switch-off: Overheating temperat- ure reached
F.22Safety switch-off: Low water pressure in the boiler
F.23Safety switch-off: Temperature difference too great (NTC1/NTC2)
F.24Safety switch-off: Temperature rise too fast
F.25Safety switch-off: Flue gas temperature too high
F.27Safety switch-off: Fault in flame detection
F.28Fault: Ignition unsuccessful when starting up
F.29Fault: Flame loss
F.32Fan frost protection function active: Fan speed outside the tolerance values
F.49eBUS fault: Voltage too low
F.61Fault: Gas valve control system
F.62Fault: Gas valve switch-off control
F.63Fault: EEPROM
F.64Fault: Electronics/sensor/analogue-to- digital converter
F.65Fault: Electronics temperature too high
F.67Value sent back by ASIC is incorrect (flame signal)
F.68Fault: Unstable flame (analogue input)
F.70Invalid product code (DSN)
F.71Fault: Flow/return temperature sensor
F.72Fault: Deviation in the water pressure sensor/return temperature sensor
F.73Fault: Water pressure sensor not con- nected or has short-circuited
F.74Fault: Electrical problem in the water pressure sensor
F.75Fault: Pressure sensor
F.76The safety cut-out in the primary heat exchanger is defective
F.77Fault: Condensate or smoke
F.78Interruption to DHW outlet sensor at external controller
F.83Fault: Dry fire
F.84Fault: Flow/return temperature sensor
F.85Fault: Temperature sensor
F.86Fault: Underfloor heating contact
F.87Fault: Electrodes
F.88Fault: Gas valve
F.89Fault: Pump
ConnectionNo 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:

CodeMeaning
F.00Interruption: Flow sensor
F.01Interruption: Return sensor
F.02Interruption: DHW outlet sensor
F.03Interruption: Cylinder sensor
F.10Short circuit: Flow sensor
F.11Short circuit: Return sensor
F.12Short circuit: DHW outlet sensor
F.13Short circuit: Cylinder sensor
F.20Safety switch-off: Temperature limiter
F.22Safety switch-off: Low water pressure
F.23Safety switch-off: Temp.spread too large
F.24Safety switch-off: Temp. incr. too fast
F.25Safety switch-off: Flue temp. too high
F.26Fault: Fuel valve not working
F.27Safety switch-off: Flame simulation
F.28Start-up failure: Ignit. unsuccessful
F.29Start-up failure: Ignit. unsuccessful
F.32Fault: Fan
F.33Pressure switch
F.35Fault: Air/flue gas duct
F.42Fault: Coding resistor
F.49Fault: eBUS
F.55Fault: CO sensor
F.56Safety switch-off: CO limit exceeded
F.57Fault: Measuring program
F.61Fault: Fuel valve actuation
F.62Fault: Fuel valve switch-off delay
F.63Fault: EEPROM
F.64Fault: Electronics/sensor
F.65Fault: Electronics temp.
F.67Fault: Electronics/flame
F.68Fault: Flame signal unstable
F.70Fault: Invalid Device Specific Number
F.71Fault: Flow sensor
F.72Fault: Flow/return sensor
F.73Fault: Water press. sensor
F.74Fault: Water press. sensor
F.75Fault: Pump/ water shortage
F.77Fault: Flue non-ret. valve/condens. pump
F.78Interrupt.: DHW outlet sensor on ext. contr.
F.80Fault: actoSTOR inlet sensor
F.81Fault: cylinder charging pump
F.82Fault: Ext. current anode
F.83Fault: NTC temp. gradient
F.84Fault: NTC temp. diff. implausible
F.85Fault: NTCs fitted incorrectly
F.90Fault: Communication
F.94Fault: Vortex and differential pressure
LED actoSTOR moduleactoSTOR electronics status
Communication faultCommunication 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:

CodeMeaning
F.00Flow temperature sensor interruption
F.01Return temperature sensor interruption
F.02Interruption cylinder charging sensor actoSTOR (NTC) only in combination with F.91
F.03Interruption cylinder sensor actoSTOR (NTC) only in combination with F.91
F.10Flow NTC short circuit
F.11Return NTC short circuit
F.12Short circuit at cylinder charging sensor (NTC) only in combination with F.91
F.13Product 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.20Safety switch-off: Temperature limiter
F.22Safety switch-off: Low water pressure
F.23Safety switch-off: Temperature difference too great
F.24Safety switch-off: Temperature rise too fast
F.25Safety switch-off: Flue gas temperature too high
F.26Fault: Gas valve without function
F.27Safety switch-off: Flame simulation
F.28Failure during start-up: Ignition unsuccess- ful
F.29Failure during operation: Re-ignition unsuc- cessful
F.32Fan fault
F.42Coding resistance fault (possible in combin- ation with F.70)
F.49Fault: eBUS
F.52Contact fault mass flow sensor/Venturi
F.53Combustion regulation fault
F.54Fault in the gas supply (in combination with F.28/F.29)
F.56Combustion component fault
F.57End comfort protection mode
F.61Gas valve actuation fault
F.62Gas valve switch-off delay
F.63Fault: EEPROM
F.64Fault: Electronics/NTC
F.65Fault: Electronics temp.
F.67Fault: Electronics/flame
F.68Fault: Unstable flame signal
F.70Invalid device specific number (DSN)
F.71Flow NTC fault
F.72Flow/return NTC fault
F.73Water pressure sensor signal in the wrong range (too low)
F.74Water pressure sensor signal outside cor- rect range (too high)
F.75Fault: No pressure change detection when starting pump
F.77Fault: Flue non-return flap/condensate pump
F.78Interruption to DHW outlet sensor at the external controller
F.80Interruption or short circuit of secondary heat exchanger inlet sensor; only in connection with F.91
F.81actoSTOR charging pump defective; only in combination with F.91
F.83Fault: Flow and/or return temperature sensor temperature change
F.84Fault: Flow/return temperature sensor tem- perature difference implausible
F.85Fault: Flow and return temperature sensors incorrectly installed
F.90Communication with actoSTOR module interrupted
F.91Sensor/actuator fault on actoSTOR module
F.92Coding resistance fault
F.93Poor combustion quality
LED actoSTOR moduleactoSTOR electronics status
Communication faultNo communication with the PCB

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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 codeMeaning
F.00Fault: Flow temperature sensor
F.01Fault: Return temperature sensor
F.10Short circuit: Flow temperature sensor
F.11Short circuit: Return temperature sensor
F.12 and F.91Short circuit: Cylinder temperature sensor
F.13Short circuit: Domestic hot water cylinder temperature sensor
F.20Safety switch-off: Overheating temperat- ure reached
F.22Safety switch-off: Low water pressure in the boiler
F.23Safety switch-off: Temperature difference too great (NTC1/NTC2)
F.24Safety switch-off: Temperature rise too fast
F.25Safety switch-off: Flue gas temperature too high
F.27Safety switch-off: Fault in flame detection
F.28Fault: Ignition unsuccessful when starting up
F.29Fault: Flame loss
F.32Fan frost protection function active: Fan speed outside the tolerance values
F.49eBUS fault: Voltage too low
F.61Fault: Gas valve control system
F.62Fault: Gas valve switch-off control
F.63Fault: EEPROM
F.64Fault: Electronics/sensor/analogue-to- digital converter
F.65Fault: Electronics temperature too high
F.67Value sent back by ASIC is incorrect (flame signal)
F.68Fault: Unstable flame (analogue input)
F.70Invalid product code (DSN)
F.71Fault: Flow/return temperature sensor
F.72Fault: Deviation in the water pressure sensor/return temperature sensor
F.73Fault: Water pressure sensor not con- nected or has short-circuited
F.74Fault: Electrical problem in the water pressure sensor
F.75Fault: Pressure sensor
F.76The safety cut-out in the primary heat exchanger is defective
F.77Fault: Condensate or smoke
F.78Interruption to DHW outlet sensor at external controller
F.83Fault: Dry fire
F.84Fault: Flow/return temperature sensor
F.85Fault: Temperature sensor
F.86Fault: Underfloor heating contact
F.87Fault: Electrodes
F.88Fault: Gas valve
F.89Fault: Pump
ConnectionNo 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:

MessagePossible cause
F.00 Interruption: Flow sensorFlow temperature sensor de- fective or not connected
F.01 Interruption: Return sensorReturn temperature sensor de- fective or not connected
F.02 Interruption: DHW outlet sensorCylinder temperature sensor for the shift-load cylinder defective or not connected
F.03 Interruption: Cylinder sensorTemperature sensor for the shift-load cylinder defective or not connected
F.10 Short circuit: Flow sensorFlow temperature sensor de- fective or has short-circuited
F.11 Short circuit: Return sensorReturn temperature sensor de- fective or has short-circuited
F.12 Short circuit: DHW outlet sensorCylinder temperature sensor defective or has short-circuited
F.13 Short circuit: Cylinder sensorWarm start sensor/cylinder tem- perature sensor defective or not connected
F.20 Safety switch-off: Tem- perature limiterMaximum 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 pressureNo/insufficient water in the product or the water pressure is too low
F.23 Safety switch-off: Temp.spread too largeTemperature spread too great. Water circulation too low
F.24 Safety switch-off: Temp. incr. too fastTemperature increase too fast
F.25 Safety switch-off: Flue temp. too highflue gas temperature too high
F.26 Fault: Fuel valve not workingGas valve assembly stepper motor defective or not connec- ted
F.27 Safety switch-off: Flame simulationMonitoring electrode reports an incorrect flame
F.28 Start-up failure: Ignit. unsuccessfulFailure during start-up or igni- tion unsuccessful. Gas pressure monitor or thermal cut-out has been triggered.
F.29 Operating failure: Ignit. unsuccessfulGas supply interrupted intermit- tently. Re-ignition failed.
F.32 Fault: FanFan defective or not connected
F.42 Fault: Coding resistorCoding resistor or gas group resistor causes a short circuit
F.49 Fault: eBUSUndervoltage on the eBUS
F.52 Mass flow sensor not connectedMass flow sensor defective or not connected
F.53 Fault: Mass flow sensorMass flow sensor defective
F.54 Fault: Boiler startNo gas inlet pressure or insuffi- cient gas inlet pressure causes faults when the product is star- ted
F.55 Fault: CO sensorAll-gas sensor defective or has short-circuited
F.56 Safety switch-off: CO limit exceededSafety shutdown after the CO limit value is exceeded
F.57 Fault: Measuring pro- gramRegulation fault caused by cor- roded ignition electrode
F.61 Fault: Fuel valve actu- ationThe gas valve assembly cannot be actuated
F.62 Fault: Fuel valve switch- off delayDelayed switch-off sequence for the gas valve after the flame is extinguished
F.63 Fault: EEPROMEEPROM faulty
F.64 Fault: Electronics/sensorElectronics, safety-relevant sensor or cable defective
F.65 Fault: Electronics temp.Electronics defective or too hot due to external influences
F.67 Fault: Electronics/flameImplausible flame signal
F.68 Fault: Flame signal un- stableFlame monitor reports an un- stable flame signal
F.70 Fault: Invalid Device Specific NumberIncorrect/missing Device Specific Number or incorrect/missing coding resistor
F.71 Fault: Flow sensorFlow temperature sensor re- turns implausible values
F.72 Fault: Flow/return sensorTemperature 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 shortageInsufficient pressure jump de- tected when starting the pump
F.77 Fault: Flue non-ret. valve/condens. pumpNo 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 sensorInlet temperature sensor defect- ive or not connected
F.81 Fault: cylinder charging pumpCylinder is not fully charged after specified time
F.82 Fault: Ext. current anodeExternal current anode defect- ive or not connected
F.83 Fault: NTC temp. gradi- entTemperature difference between flow and return temperature sensor is too small
F.84 Fault: NTC temp. diff. implausibleTemperature difference is im- plausible
F.85 Fault: NTCs fitted incor- rectlyFlow/return temperat- ure sensors returning incorrect/implausible values
F.90 Fault: CommunicationCommunication with actoSTOR interrupted
F.91 Fault: actoSTOR sensorSensor on the actoSTOR is defective
F.92 Fault: Incorrect gas typeThe coding resistor on the PCB does not match the gas group that is entered
F.93 Fault: Check gas routeCombustion quality outside the permitted range
F.94 Fault: Vortex and differen- tial pressureSensors return implausible val- ues.
LED actoSTOR Modul actoSTOR communication statusactoSTOR communication status: Not connected, Con- nection error, Connection active
Communication faultCommunication 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:

CodeMeaning
F.00Interruption: Flow sensor
F.01Interruption: Return sensor
F.02Interruption: DHW outlet sensor
F.03Interruption: Cylinder sensor
F.10Short circuit: Flow sensor
F.11Short circuit: Return sensor
F.12Short circuit: DHW outlet sensor
F.13Short circuit: Cylinder sensor
F.20Safety switch-off: Temperature limiter
F.22Safety switch-off: Low water pressure
F.23Safety switch-off: Temp.spread too large
F.24Safety switch-off: Temp. incr. too fast
F.25Safety switch-off: Flue temp. too high
F.26Fault: Fuel valve not working
F.27Safety switch-off: Flame simulation
F.28Start-up failure: Ignit. unsuccessful
F.29Start-up failure: Ignit. unsuccessful
F.32Fault: Fan
F.33Pressure switch
F.35Fault: Air/flue gas duct
F.42Fault: Coding resistor
F.49Fault: eBUS
F.55Fault: CO sensor
F.56Safety switch-off: CO limit exceeded
F.57Fault: Measuring program
F.61Fault: Fuel valve actuation
F.62Fault: Fuel valve switch-off delay
F.63Fault: EEPROM
F.64Fault: Electronics/sensor
F.65Fault: Electronics temp.
F.67Fault: Electronics/flame
F.68Fault: Flame signal unstable
F.70Fault: Invalid Device Specific Number
F.71Fault: Flow sensor
F.72Fault: Flow/return sensor
F.73Fault: Water press. sensor
F.74Fault: Water press. sensor
F.75Fault: Pump/ water shortage
F.77Fault: Flue non-ret. valve/condens. pump
F.78Interrupt.: DHW outlet sensor on ext. contr.
F.80Fault: actoSTOR inlet sensor
F.81Fault: cylinder charging pump
F.82Fault: Ext. current anode
F.83Fault: NTC temp. gradient
F.84Fault: NTC temp. diff. implausible
F.85Fault: NTCs fitted incorrectly
F.90Fault: Communication
F.94Fault: Vortex and differential pressure
LED actoSTOR moduleactoSTOR electronics status
Communication faultCommunication 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:

MessagePossible cause
F.00 Flow temperature sensor interruptionNTC plug loose/not plugged in
NTC sensor defective
Multiple plug loose/not plugged in
Interruption in the cable harness
F.01 Return temperature sensor interruptionNTC plug loose/not plugged in
NTC sensor defective
Multiple plug loose/not plugged in
Interruption in the cable harness
F.03 Cylinder temperature sensor interruptionNTC sensor defective
NTC plug loose/not plugged in
Connection to cylinder electron- ics defective
F.10 Flow temperature sensor short circuitNTC sensor defective
Short circuit in the cable har- ness
F.11 Return temperature sensor short circuitNTC sensor defective
Short circuit in the cable har- ness
F.13 Cylinder temperature sensor short circuitNTC sensor defective
Short circuit in the cable har- ness
F.20 Safety shutdown: Safety cut-outFlow NTC defective
Return NTC defective
Earth connection faulty
Stray spark via the ignition cable, ignition plug or ignition electrode
F.22 Safety shutdown: Water deficiencyInsufficient/no water in the product.
Interruption in the cable harness
F.23 Safety shutdown: Temper- ature spread too greatPump blocked
Pump runs with insufficient out- put
Flow and return NTC connected the wrong way round
F.24 Safety shutdown: Temper- ature rise too fastPump 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 highFlue gas safety cut-out plug is not plugged in or is loose
Interruption in the cable harness
F.27 Safety shutdown: Flame simulationGas solenoid valve not leak- tight
Moisture on the PCB
Flame monitor defective
F.28 Ignition unsuccessfulGas 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 outGas 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 faultPlug 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 faultAir/flue pipe blocked
Defective air pressure switch
Cable connections not plugged in/loose
Fan defective
F.33 Air pressure switch faultPCB defective
Excessive counter-pressure in the air/flue pipe
F.49 Fault: eBUSeBUS overload
Short circuit in the eBUS con- nection
Different polarities at the eBUS connection
F.61 Gas safety valve drive faultShort circuit in the cable har- ness
Gas valve assembly defective
PCB defective
F.62 Gas safety valve connec- tion faultPCB defective
The connection to the gas valve assembly has been interrup- ted/broken
F.63 Fault: EEPROMPCB defective
F.64 Fault: Electronics/NTCFlow NTC short circuit.
Return NTC short circuit
PCB defective
F.65 Electronics temperature faultElectronics overheated
PCB defective
F.67 Flame plausibility faultPCB 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 faultThe 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 faultFlow 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- ciencyMalfunction
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- ciencyD.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 changeWater deficiency
Flow NTC: No contact
Return NTC: No contact
F.84 Fault: Temperature differ- ence at the flow and return tem- perature sensorsFlow 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:

CodeMeaning
F. 0Flow temperature sensor interruption
F. 1Return temperature sensor interruption
F.10Flow NTC short circuit
F.11Return NTC short circuit
F.13Cylinder temperature sensor short circuit
F.20Safety switch-off: Temperature limiter
F.22Safety switch-off: Low water pressure
F.23Safety switch-off: Temperature difference too great
F.24Safety switch-off: Temperature rise too fast
F.27Safety switch-off: Flame simulation
F.28Failure during start-up: Ignition unsuccessful
F.29Failure during operation: Re-ignition unsuccess- ful
F.32Fan fault
F.49Fault: eBUS
F.61Gas valve actuation fault
F.62Gas valve switch-off delay
F.63Fault: EEPROM
F.64Fault: Electronics/NTC
F.65Fault: Electronics temp.
F.67Fault: Electronics/flame
F.70Invalid device specific number (DSN)
F.71Flow NTC fault
F.72Flow/return NTC fault
F.73Water pressure sensor signal in the wrong range (too low)
F.74Water pressure sensor signal outside correct range (too high)
F.75Fault: No pressure change detection when start- ing pump
F.77Fault: Flue non-return flap/condensate pump
conNo communication with the PCB

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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 codeMeaning
F.00Fault: Flow temperature sensor
F.01Fault: Return temperature sensor
F.10Short circuit: Flow temperature sensor
F.11Short circuit: Return temperature sensor
F.12 and F.91Short circuit: Cylinder temperature sensor
F.13Short circuit: Domestic hot water cylinder temperature sensor
F.20Safety switch-off: Overheating temperat- ure reached
F.23Safety switch-off: Temperature difference too great (NTC1/NTC2)
F.24Safety switch-off: Temperature rise too fast
F.25Safety switch-off: Flue gas temperature too high
F.27Safety switch-off: Fault in flame detection
F.28Fault: Ignition unsuccessful when starting up
F.29Fault: Flame loss
F.32Fan frost protection function active: Fan speed outside the tolerance values
F.49eBUS fault: Voltage too low
F.61Fault: Gas valve control system
F.62Fault: Gas valve switch-off control
F.63Fault: EEPROM
F.64Fault: Electronics/sensor/analogue-to- digital converter
F.65Fault: Electronics temperature too high
F.67Value sent back by ASIC is incorrect (flame signal)
F.68Fault: Unstable flame (analogue input)
F.70Invalid product code (DSN)
F.71Fault: Flow/return temperature sensor
F.72Fault: Deviation in the water pressure sensor/return temperature sensor
F.77Fault: Condensate or smoke
F.78Interruption to DHW outlet sensor at external controller
F.83Fault: Dry fire
F.84Fault: Flow/return temperature sensor
F.85Fault: Temperature sensor
F.86Fault: Underfloor heating contact
F.87Fault: Electrodes
F.88Fault: Gas valve
ConnectionNo 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:

CodeMeaning
F.00Flow temperature sensor interruption
F.01Return temperature sensor interruption
F.10Flow NTC short circuit
F.11Return NTC short circuit
F.13Warm start sensor/cylinder sensor short circuit
F.22Safety switch-off: Low water pressure
F.23Safety switch-off: Temperature difference too great
F.24Safety switch-off: Temperature rise too fast
F.25Safety switch-off: Flue gas temperature too high
F.27Safety switch-off: Flame simulation
F.28Failure during start-up: Ignition unsuccessful
F.29Failure during operation: Re-ignition unsuccess- ful
F.32Fan fault
F.49Fault: eBUS
F.61Fault: Gas valve regulation
F.62Fault: Gas valve switch-off delay
F.63Fault: EEPROM
F.64Fault: Electronics/NTC
F.65Fault: Electronics temp.
F.67Fault: Electronics/flame
F.68Fault: Unstable flame signal
F.70Invalid device specific number (DSN)
F.71Flow NTC fault
F.72Flow/return NTC fault
F.73Water pressure sensor signal in the wrong range (too low)
F.74Water pressure sensor signal outside correct range (too high)
F.75Fault: No pressure change detection when start- ing pump
F.76Overheating protection on primary heat ex- changer has responded
F.77Fault: Flue non-return flap/condensate pump
F.83Fault: Flow and/or return temperature sensor temperature change
F.85Fault: Flow and return temperature sensors incorrectly installed
F.87Ignition transformer not connected
F.88Gas valve not connected
F.89Incorrect pump detected
conNo communication with the PCB

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