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Boiler Fault Codes

ManufacturerMakeFaultDetails
Worcester BoschCDI ClassicA1Water is leaking or the pump needs replacing or freeing due to the pump running dry.
Worcester BoschCDI ClassicA7The hot water negative thermistor coefficient (NTC) sensor is defective – the hot water sensor or connecting leads need checking.
Worcester BoschCDI ClassicA8Break communication to FX sensor controls electrical connections need checking.
Worcester BoschCDI ClassicB1Code plug not detected .
Worcester BoschCDI ClassicC6Fan speed too low – the fan lead and connector need checking and may need replacing.
Worcester BoschCDI ClassicE2Central heating (CH) water flow negative thermistor coefficient (NTC) sensor defective check CH flow NTC sensor and connection leads.
Worcester BoschCDI ClassicE9Safety temperature limiter in central heating (CH) flow has tripped the system pressure or safety temperature limiter needs checking
Worcester BoschCDI ClassicEAFlame not detected due to a gas issue – the gas supply, power supply or igniter, electrode and lead need checking – contact a Gas Safe installer.
Worcester BoschCDI ClassicF0Internal error – electrical connector contacts or programmer interface module – check ignition leads are not loose.
Worcester BoschCDI ClassicF7Flame detected even though the appliance is switched off – check the electrode assembly is dry and the pcb and flue are clear.
Worcester BoschCDI ClassicFAFlame detected after gas shut off – the gas valve needs checking – hire a Gas Safe installer.
Worcester BoschCDI ClassicFDReset button pressed by mistake – press reset button again.
Worcester BoschCDI HighflowA1Pump dry run detection or pump is running in air the system pressure needs checking
Worcester BoschCDI HighflowA5Tank negative thermistor coefficient (NTC) defect
Worcester BoschCDI HighflowA7Domestic hot water (DHW) negative thermistor coefficient (NTC) defect
Worcester BoschCDI HighflowA8Energy Management System (EMS) communication error
Worcester BoschCDI HighflowB1Code plug not detected
Worcester BoschCDI HighflowB2, B3, B4, B5, B6Data error
Worcester BoschCDI HighflowB7Burner control error
Worcester BoschCDI HighflowC6Fan defect
Worcester BoschCDI HighflowD3External temperature limiter
Worcester BoschCDI HighflowD5Condensate pump failure
Worcester BoschCDI HighflowD6Internal heat bank overflow
Worcester BoschCDI HighflowEAFlame not detected
Worcester BoschCDI HighflowE2Primary negative thermistor coefficient (NTC) defect
Worcester BoschCDI HighflowE9Safety temperature limiter in central heating (CH) flow stat tripped
Worcester BoschCDI HighflowF0Internal error
Worcester BoschCDI HighflowF1ROM fault
Worcester BoschCDI HighflowF7Flame detected after appliance has been shut off
Worcester BoschCDI HighflowFAFlame detected after gas shut off
Worcester BoschCDI HighflowFDReset button pressed – try pressing the reset button again
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemT1Ignition test – checking the igniter spark
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemT2Fan test – checking the basic fan
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemT3Pump test – checking the basic pump
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemT4Three way valve test
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemT6Ionisation oscillator test
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I System9A 362error – incorrect HCM fitted
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I System9U 233Heat Control Module (HCM) error – problem with code plug
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemB7 257Internal error – possible control board problem
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemC6 215Fan problem – fan running too fast
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemC7 214Fan problem – fan not running
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemD1 240Return sensor error – sensor may be wet or damaged
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemE2 222Flow sensor short circuit error
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemE5 218Flow temperature too high
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemE9 219Safety sensor fault – temperature too high, sensor short circuit or open circuit
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemEA 227No flame detected or flame signal loss during operation
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemF0 237Internal error
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemF7 228Flame error – false flame or flame detected before burner started
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemFA 306False flame fault – flame detected after burner stop
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemFD 231Mains power fault – electrical power interruption
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemFA 364Gas valve EV2 leak test failed – gas valve leak
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemFB 365Gas valve EV1 leak test failed
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemA1 281Pump stuck or running with air in the system
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemC1 264Airflow stopped during operation
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemC4 273Airflow present during last 24 hour
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemD1 240Return sensor short circuit
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemD4 271Temperature difference between flow and safety sensor exceeds limit
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemE9 224Max thermostat activated – flue gas thermostat overheat
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemEA 227No ionisation detected after ignition
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemEF 349Central heating boil detected – boiler operating at minimum burner load with temperature difference greater than 18°C between Flow & Return.
Worcester BoschCDi Compact / Greenstar Si / Greenstar 27/30 I SystemNO CODE 212Safety or flow temperature rising too fast
Worcester BoschGreenstar I226Service tool has been connected in the blocking error history menu
Worcester BoschGreenstar IFD 231The power has been interrupted during a lockout
Worcester BoschGreenstar IC7 214Fan does not run during the start up phase – fan harness connector needs checking
Worcester BoschGreenstar IC6 215Fan speed too high – check the fan harness and connector
Worcester BoschGreenstar IC7 216Fan speed too low – check the fan harness and connector
Worcester BoschGreenstar IC7 217Fan has stopped during appliance operation
Worcester BoschGreenstar IC1 264Fan stopped during operation
Worcester BoschGreenstar IC4 273Continuous fan operation for the last 24 hours – appliance temporarily blocked
Worcester BoschGreenstar IE2 222Flow temperature sensor shorted
Worcester BoschGreenstar IE2 233Flow temperature sensor disconnected
Worcester BoschGreenstar IE9 276Primary flow temperature exceeded 95°c
Worcester BoschGreenstar IE2 350Flow temperature sensor shorted
Worcester BoschGreenstar IE2 351Flow temperature sensor disconnected
Worcester BoschGreenstar IFA 306Ionisation detected after the gas valve closed
Worcester BoschGreenstar IEA 227No ionisation detected after ignition
Worcester BoschGreenstar IF7 228Isioniation current detected before burner start
Worcester BoschGreenstar IEA 229Loss of ionisation signal during operation
Worcester BoschGreenstar IEA 261Heat control module (HCM) potentially defective – reset the appliance
Worcester BoschGreenstar I9U 233Control box or heat control module (HCM) is defective or loose, the HCM needs to be checked
Worcester BoschGreenstar IC4 237Control box or heat control module (HCM) is defective
Worcester BoschGreenstar IF0 238Gas valve or control box error – gas valve coils need checking
Worcester BoschGreenstar IF0 239Control box or the heat control module (HCM) is defective – the control box connections need checking
Worcester BoschGreenstar IF0 242Control box or the heat control module (HCM) is defective – the HCM and control box connections need to be checked
Worcester BoschGreenstar IB7 257Control box or the heat control module HCM) is defective- the HCM and control box connections need to be checked
Worcester BoschGreenstar IF0 258Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked
Worcester BoschGreenstar IEH 258Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked
Worcester BoschGreenstar IF1 259Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked
Worcester BoschGreenstar IF0 262Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked
Worcester BoschGreenstar IF1 263Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked
Worcester BoschGreenstar IF0 272Control box or the heat control module (HCM) is defective – control box and connections need checking or HCM might not be inserted properly and need replacing
Worcester BoschGreenstar IF0 280Control box or the heat control module (HCM) is defective – control box and connections need checking or HCM might not be inserted properly and need replacing
Worcester BoschGreenstar IF0 290Control box is defective – HCM needs checking as it might not be inserted properly or need replacing
Worcester BoschGreenstar I328Internal error with the mains voltage – frequency may be inconsistent
Worcester BoschGreenstar I235Incompatible heat control module (HCM) software versions – control box needs latest software
Worcester BoschGreenstar I356Low mains voltage – the voltage may be interrupted or inconsistent and needs checking
Worcester BoschGreenstar I360Heat control module (HCM) invalid – the inserted HCM does not correspond with the control box
Worcester BoschGreenstar IA8 362Low mains voltage – the voltage may be interrupted, inconsistent or heat control module (HCM) invalid
Worcester BoschGreenstar ICC 800Outdoor sensor defect available when accessory outdoor sensor is connected
Worcester BoschGreenstar IA1 281Pump stock or running dry
Worcester BoschGreenstar IE9 224Flue or high limit thermostat activated
Worcester BoschGreenstar ID4 341Primary flow temperature rising too fast
Worcester BoschGB162208The boiler is in chimney sweep mode
Worcester BoschGB162200The boiler is in heating mode
Worcester BoschGB162201The boiler is in domestic hot water (DHW) mode
Worcester BoschGB162202The boiler is waiting – there was a heat demand from the on off or modulating control
Worcester BoschGB162203The boiler is on standby
Worcester BoschGB162204The boiler is waiting – the actual temperature is higher than the calculated or selected boiler temperature
Worcester BoschGB162212The temperature recorded by the flow temperature sensor or the safety sensor is rising too quickly
Worcester BoschGB162226Diagnosis tool was connected and is now locked out
Worcester BoschGB162260The flow temperature sensor is not detecting a rise in temperature following a burner start
Worcester BoschGB162265The boiler is waiting in response to a heat demand – the boiler regularly switches to partial load
Worcester BoschGB162268Component test phase
Worcester BoschGB162270The boiler is modulating upwards
Worcester BoschGB162283The boiler is preparing for a burner start – the fan and pump are activated
Worcester BoschGB162284The gas valve is switched
Worcester BoschGB162305The boiler is waiting for domestic hot water (DHW) operation to end
Worcester BoschGB162235The KIM (boiler identification module) is too new for the burner control unit
Worcester BoschGB162360The KIM that has been fitted is not compatible with the burner control unit
Worcester BoschGB1629A 361The burner control unit that has been fitted is not compatible with the KIM (boiler identification module)
Worcester BoschGB1629U 233The burner control unit or KIM (boiler identification module) is faulty
Worcester BoschGB162A3 317Short circuit in the flue gas temperature sensor contacts
Worcester BoschGB162B7 257The burner control unit or the KIM (boiler identification module) is faulty
Worcester BoschGB162C1 264No control signal or power supply to the fan during operation
Worcester BoschGB162C4 273The boiler was switched off for a maximum of 2 minutes because it had been operating continuously for more than 24 hours
Worcester BoschGB162C6 215The fan speed is too high
Worcester BoschGB162C6 216The fan speed is too low
Worcester BoschGB162C7 214The fan does not run during the start phase
Worcester BoschGB162C7 217The fan speed is irregular when starting up
Worcester BoschGB162CE 207Water pressure is too low
Worcester BoschGB162CE 266Pump test failed
Worcester BoschGB162D1 240The contacts of the boiler return temperature sensor have been short circuited
Worcester BoschGB162D1 241The contacts of the boiler return temperature sensor have been interrupted
Worcester BoschGB162D3 232The external switching contact has opened
Worcester BoschGB162D4 213The actual temperature recorded by the flow temperature sensor or return temperature sensor is rising too quickly
Worcester BoschGB162D4 271Actual temperature differential between flow and safety temperature sensor is too high
Worcester BoschGB162D4 286The boiler return temperature sensor has detected a return temperature higher than 105°c
Worcester BoschGB162E2 222Short circuit in the flow temperature sensor contacts
Worcester BoschGB162E2 223The flow temperature sensor contacts have been interrupted
Worcester BoschGB162E5 218The temperature captured by the flow temperature sensor exceeded 105°c
Worcester BoschGB162E9 210The temperature measured by the flue gas sensor is too high and is open
Worcester BoschGB162E9 219The safety temperature sensor has captured a temperature in excess of 105°C
Worcester BoschGB162E9 220The contacts for the safety temperature sensor have shorted or the safety temperature sensor has detected a temperature higher than 130°c
Worcester BoschGB162E9 224The contacts of the safety temperature sensor have been interrupted
Worcester BoschGB162E9 276The temperature flow sensor has measured a temperature in excess of 95°c
Worcester BoschGB162E9 277The safety temperature sensor has measured temperature in excess of 95°c
Worcester BoschGB162E9 285The boiler return temperature sensor has measured a temperature higher than 95°c
Worcester BoschGB162E9 318The flue gas temperature sensor contacts have been interrupted
Worcester BoschGB162EA 227An insufficient ionisation current was measured following ignition of the burner
Worcester BoschGB162EA 229The ionisation current detected by the system during the burning phase was insufficient
Worcester BoschGB162EA 234The contacts of the gas valve have been interrupted
Worcester BoschGB162EA 261The burner control unit is faulty
Worcester BoschGB162EA 269The ignition device has been activated for too long
Worcester BoschGB162F0 238The burner control unit KIM (boiler identification module) is faulty
Worcester BoschGB162F0 239The burner control unit KIM (boiler identification module) has an error. Cabling might have poor contact breaks and pinching or the plug and wiring of the burner control unit needs checking, also check the operating characteristics of the boiler by replacing the burner control unit.
Worcester BoschGB162F0 242, F0 243. F0 244. F0 245, F0 246. F0 247, F0 248, F0 249, F0 250, F0 251, F0 252, F0 253, F0 255, F0 259, F0 263, F0 267, F0 272The burner control unit (KIM) is faulty – the wiring of the burner control unit needs checking, also check the operating characteristics of the boiler by replacing the burner control unit.
Worcester BoschGB162F0 278The sensor test has failed – cabling and plug sensors need checking
Worcester BoschGB162F0 279The burner control unit, or KIM, is faulty – control unit may need replacing
Worcester BoschGB162F0 280The burner control unit is faulty
Worcester BoschGB162F0 287The burner control unit, or KIM, has an error
Worcester BoschGB162F0 290The burner control unit, or KIM, is faulty
Worcester BoschGB162F7 228An ionisation current was measured before the burner started
Worcester BoschGB162F7 328A brief power failure has occurred
Worcester BoschGB162FA 306An ionisation current was measured after the burner went out
Worcester BoschGB162FD 231The mains voltage was interrupted during an interlocking fault
Worcester BoschGB162EC 256The burner control unit has an error
Worcester BoschGB162EH 258The burner control unit is faulty – check the plug and wiring of the burner control unit.
Worcester BoschGB162H07The current water pressure is too low, limiting the performance in heat mode as well as domestic hot water (DHW) mode
Worcester BoschGB162HrEThe boiler keeps resetting
Worcester BoschGB162rEThe boiler resets
Worcester BoschHighflowLight offNo boiler demand
Worcester BoschHighflowLight onHeating demand on boiler is OK
Worcester BoschHighflow1 flash 5 seconds offNo ionisation detected after ignition
Worcester BoschHighflow2 flashes 5 seconds offLoss of ionisation signal during operation
Worcester BoschHighflow3 flashes 5 seconds offGas valve error
Worcester BoschHighflow4 flashes 5 seconds offFirst safety timing error / ignition timing error
Worcester BoschHighflow5 flashes 5 seconds offIonisation detected after burner stopped, Gas valve EV2 leak test failed, Gas valve EV1 leak test failed, Ionisation current detected before burner start, Gas valve error, Ionisation sensor shorted
Worcester BoschHighflow4 flashes 5 second gap 1 long flashSensor test failed
Worcester BoschHighflow4 flashes, 5 second gap, 2 long flashesSafety temperature too high
Worcester BoschHighflow4 flashes, 5 second gap, 3 long flashesMax safety thermostat activated
Worcester BoschHighflow4 flashes, 5 second gap, 4 long flashesReturn temperature too high
Worcester BoschHighflow4 flashes, 5 second gap, 5 long flashesFlow temperature too high – supply sensor exceeded 110°c
Worcester BoschHighflow1 long flash, 4 quick flashes, 5 second gap, 1 long flash, 4 quick flashesHeating control module (HCM) defective
Worcester BoschHighflow2 long flashes, 4 quick flashes, 5 second gap, 2 long flashes, 4 quick flashesFan running too fast, Fan running too slow, No airflow after defined period of time, Fan not running
Worcester BoschHighflow3 long flashes, 4 quick flashes, 5 second gap, 3 long flashes, 4 quick flashesMains voltage interrupted after locking error
Worcester BoschHighflow4 long flashes, 4 quick flashes, 5 second gap, 4 long flash, 4 quick flashesInternal control board faults
Worcester BoschHighflow5 long flashes, 4 quick flashes, 5 second gap, 5 long flash, 4 quick flashesAll other miscellaneous faults – reset the boiler by turning the control knob anti-clockwise to the reset position
Worcester BoschGreenstar RiNo lightNo power at control board
Worcester BoschGreenstar RiLight onAppliance on but not operating during demand
Worcester BoschGreenstar RiSlow flash ( mostly off flashes on)Ignition lockout
Worcester BoschGreenstar RiSlow flash ( mostly on flashes off)Flue overheat or heat exchanger overheat
Worcester BoschGreenstar RiFast flashVolatile lockout sensor fan or code plug
Worcester BoschGreenstar Ri2 pulsesCheck service mode switch is in minimum position
Worcester BoschGreenstar Ri5 pulsesCheck service mode switch is in max position
Worcester BoschGreenstar 8000200 OBoiler in heating mode
Worcester BoschGreenstar 8000201 OBoiler in hot water mode
Worcester BoschGreenstar 8000202 OBoiler in anti-cycle mode
Worcester BoschGreenstar 8000203 0Boiler in standby – no heat energy demand
Worcester BoschGreenstar 8000204 OCurrent primary water temperature higher than set value
Worcester BoschGreenstar 8000208 0Chimney sweep demand
Worcester BoschGreenstar 8000224 VSafety temperature limiter has tripped – top-up water until the reset pressure is reached
Worcester BoschGreenstar 8000227 VNo flame signal after ignition burner control unit could need replacing
Worcester BoschGreenstar 8000228 VFlame signal without flame present – air/gas ratio control valve may need replacing as might the ionisation cable
Worcester BoschGreenstar 8000305 0Boiler in hot water anti-cycle mode
Worcester BoschGreenstar 8000306 VFlame signal after closing the fuel supply – the air/gas ratio control valve might need replacing
Worcester BoschGreenstar 8000360 VIncompatible code plug – check if a correct code plug is installed and exchange or reconnect code plug
Worcester BoschGreenstar 8000815 W/BLow loss header temperature sensor faulty – check the sensor port or check the differential sensor for incorrect installation position or breakage
Worcester BoschGreenstar 80001010 ONo BUS communication cable, EMS-Bus isn’t connected or damaged – connect the cable for the EMS-Bus or replace the damaged cable exchange fuse
Worcester BoschGreenstar 80001017 WWater pressure too low – the water needs topping up and the vent system or pressure sensor may need replacing
Worcester BoschGreenstar 80001021 BHot water temperature sensor is defective – the plug to the hot water temperature sensor may not be connected
Worcester BoschGreenstar 80001022 BHot water storage temperature sensor is defective – connect the plug to the hot water temperature sensor correctly, mount the hot water temperature sensor correctly or replace the hot water temperature sensor
Worcester BoschGreenstar 80001037 WOutside temperature sensor is defective – check the connecting lead
Worcester BoschGreenstar 80001065 BPressure sensor defective or not connected – check pressure sensor connection as it may need replacing
Worcester BoschGreenstar 80001068 WOutside temperature sensor defective – check the connecting lead
Worcester BoschGreenstar 80001073 WShort circuit of the flow temperature sensor – the temperature sensor may need replacing
Worcester BoschGreenstar 80001074 WNo signal from the flow temperature sensor available – connect the plug to the flow temperature sensor correctly or temperature sensor could need replacing
Worcester BoschGreenstar 80001075 WShort circuit of the temperature sensor at the heating block – temperature sensor may need replacing
Worcester BoschGreenstar 80001076 WNo signal from the temperature sensor at the heating block available – replace the temperature sensor, the connecting lead or the control unit
Worcester BoschGreenstar 80002920 VError with the flame monitoring
Worcester BoschGreenstar 80002924 VNo feedback from the modulating gas valve. The gas valve relay is defective – press the reset button and apply burner start, wait to see if fault reoccurs, if it does the gas valve needs replacing
Worcester BoschGreenstar 80002925 VFeedback from the modulating gas valve is too low
Worcester BoschGreenstar 80002927 BFlame failed during burner operation. Open the main shut off valve, shut down the appliance and check gas line, replace the ionisation electrode, set burner correctly and minimum rated load, check the integrity flue system and if the interconnected room air supply is too small, or the size of the ventilation opening is too small, clean the heating block on the flue gas side or replace the control unit/burner control unit
Worcester BoschGreenstar 80002946 VIncorrect code plug detected – the code plug needs replacing
Worcester BoschGreenstar 80002948 BNo flame signal. With low output the burner starts automatically after cleaning. If the fault occurs repeatedly, the setting of the CO2 valves need checking
Worcester BoschGreenstar 80002950 BNo flame signal. Following starting procedure the burner starts automatically. After cleaning set the correct gas / air ratio correctly
Worcester BoschGreenstar 80002963 BSignal from flow and heat exchanger temperature sensor outside the permissible range – the connecting lead needs connecting correctly
Worcester BoschGreenstar 80002964 BFlow rate in heat exchanger is too low
Worcester BoschGreenstar 80002965 BFlow temperature too high
Worcester BoschGreenstar 80002966 BFlow temperature rise in heat exchanger too rapid
Worcester BoschGreenstar 80002967 BFlow / heat exchanger temperature sensor differential too great
Worcester BoschGreenstar 80002970 BPressure drop in heating system too rapid
Worcester BoschGreenstar 80002971 BSystem pressure too low – the heating system needs venting or water needs topping up until the preset pressure is reached. Replace the cable to the pressure sensor replace the pressure sensor
VaillantTurbomax Plus 824/828EF.00NTC FAULTS
VaillantTurbomax Plus 824/828E
VaillantTurbomax Plus 824/828EF.01NTC FAULTS (feed temperature sensor)
VaillantTurbomax Plus 824/828E– faulty connection and open circuit.
VaillantTurbomax Plus 824/828EF.10NTC FAULTS (feed temperature sensor) – short circuit
VaillantTurbomax Plus 824/828EF.11
VaillantTurbomax Plus 824/828EF.13NTC FAULTS (feed temperature sensor) – short circuit
VaillantTurbomax Plus 824/828EF.20NTC FAULTS (feed temperature sensor)
VaillantTurbomax Plus 824/828E
VaillantTurbomax Plus 824/828EF.22DRY FIRE, LOW WATER IN SYSTEM/OVERHEAT
VaillantTurbomax Plus 824/828E
VaillantTurbomax Plus 824/828EF.24LOW WATER, OR PUMP FAILURE/BLOCKAGE
VaillantTurbomax Plus 824/828E
VaillantTurbomax Plus 824/828E
VaillantTurbomax Plus 824/828EF.28NO IGNITION/IGNITION PROBLEM
VaillantTurbomax Plus 824/828E
VaillantTurbomax Plus 824/828EF.29FLAME EXTINGUISHED. FAN/FLUE PROBLEM/GAS
VaillantTurbomax Plus 824/828E
VaillantTurbomax Plus 824/828EF.60GAS VALVE CONTROL – DEFECTIVE
VaillantTurbomax Plus 824/828E
VaillantTurbomax Plus 824/828EF.61GAS VALVE CONTROL – DEFECTIVE
VaillantTurbomax Plus 824/828E
VaillantTurbomax Plus 824/828EF.62DEFECTIVE GAS VALVE CLOSURE MECHANISM
VaillantTurbomax Plus 824/828EF.63EEPROM (Electrically Erasable Programmable Read-Only Memory) ERROR
VaillantTurbomax Plus 824/828EF.64ELECTRONIC SYSTEM/SENSOR FAULT
VaillantTurbomax Plus 824/828EF.65ELECTRONIC SYSTEM TEMPERATURE TOO HIGH
VaillantTurbomax Plus 824/828EF.67ELECTRONIC FAULT IN FLAME SYSTEM
VaillantEcoMax Pro 18/28EF.1Lack of gas, a fault with the ignition or flue or you may need to adjust the gas valve or replace a defective electrode lead.
VaillantEcoMax Pro 18/28EF.4Ignition fault.
VaillantEcoMax Pro 18/28EF.5The system has suffered a fault due to overheating.
VaillantEcoMax Pro 18/28EF.6Your flow NTC has developed a fault.
VaillantEcoMax Pro 18/28EF.17Check the polarity of your system.
VaillantEcoMax Pro 18/28EF.24Pump-related faults – the pump could have failed, it may have over run or there could be an issue with the airlock
VaillantEcomax Pro 828EF.00, .04, .05, .10, .14, .15All of these are NTC faults, and are best resolved by first changing all NTC to make diagnosis earlier.
VaillantEcomax Pro 828EF.21The pilot flame has failed.
VaillantEcomax Pro 828EF.22There is insufficient water in your system.
VaillantEcomax Pro 828EF.11A blockage in the appliance is preventing the system from flowing as it should.
VaillantEcomax Pro 828EF.12A blockage in the appliance is affecting the system’s pressure.
VaillantEcomax Pro 828EF.13The appliance is blocked because of a water deficiency.
VaillantEcoTEC 65kWS.0Heating issue, no heat demand
VaillantEcoTEC 65kWS.1Fan start-up error
VaillantEcoTEC 65kWS.2Pump flow error
VaillantEcoTEC 65kWS.3Heating mode error – ignition problem
VaillantEcoTEC 65kWS.4Heat mode – burner on error
VaillantEcoTEC 65kWS.6Heating mode – fan overrun error
VaillantEcoTEC 65kWS.7Heating mode – pump overrun error
VaillantEcoTEC 65kWS.8Heating remaining cut off for XX amount of time
VaillantEcoTEC 65kWS.31No heat demand summer operating mode
VaillantEcoTEC 65kWS.34Heating mode frost protection error
VaillantEcoTEC 65kWS.20Hot water requirement error
VaillantEcoTEC 65kWS.22Hot water handling pump flow error
VaillantEcoTEC 65kWS.24Hot water operation burner is on
VaillantEcoTEC 65kWS.85Service message quantity of circulation water
VaillantEcoTEC Pro / EcoTEC PlusF.00 / F.0Flow temperature sensor interruption
VaillantEcoTEC Pro / EcoTEC PlusF.01 / F.1Return temperature sensor interruption
VaillantEcoTEC Pro / EcoTEC PlusF.10Flow NTC short circuit
VaillantEcoTEC Pro / EcoTEC PlusF.11Return NTC short circuit
VaillantEcoTEC Pro / EcoTEC PlusF.20Safety switch off temperature limiter
VaillantEcoTEC Pro / EcoTEC PlusF.22Safety switch off low water pressure
VaillantEcoTEC Pro / EcoTEC PlusF.23Safety switch off temperature difference too great
VaillantEcoTEC Pro / EcoTEC PlusF.24Safety switch off temperature is rising to fast
VaillantEcoTEC Pro / EcoTEC PlusF.25Safety switch off flue gas temperature too high
VaillantEcoTEC Pro / EcoTEC PlusF.26Error with gas valve – possible no function
VaillantEcoTEC Pro / EcoTEC PlusF.27Safety switch off flame simulation
VaillantEcoTEC Pro / EcoTEC PlusF.28Failure during start up – ignition unsuccessful to start
VaillantEcoTEC Pro / EcoTEC PlusF.29Failure during operation – re-ignition unsuccessful
VaillantEcoTEC Pro / EcoTEC PlusF.32Fan error
VaillantEcoTEC Pro / EcoTEC PlusF.49eBUS error – possible short circuit
VaillantEcoTEC Pro / EcoTEC PlusF.61Error with gas valve regulation
VaillantEcoTEC Pro / EcoTEC PlusF.62Error with gas valve – switch off delay
VaillantEcoTEC Pro / EcoTEC PlusF.63EEPROM error
VaillantEcoTEC Pro / EcoTEC PlusF.64Electronics / NTC error
VaillantEcoTEC Pro / EcoTEC PlusF.65Electronic temperature error could be overheating due to external influences
VaillantEcoTEC Pro / EcoTEC PlusF.67Electronics flame signal error
VaillantEcoTEC Pro / EcoTEC PlusF.68Unstable flame signal error air in gas
VaillantEcoTEC Pro / EcoTEC PlusF.70Invalid device specific number (DSN)
VaillantEcoTEC Pro / EcoTEC PlusF.71Flow NTC error – flow temperature sensor signal constant value
VaillantEcoTEC Pro / EcoTEC PlusF.72Flow return NTC error – temperature difference too great
VaillantEcoTEC Pro / EcoTEC PlusF.73Water pressure sensor signal in the wrong range, it is too low
VaillantEcoTEC Pro / EcoTEC PlusF.74Water pressure sensor signal outside correct range, the sensor signal is too high
VaillantEcoTEC Pro / EcoTEC PlusF.75Error with pressure – no pressure change detection when starting the pump
VaillantEcoTEC Pro / EcoTEC PlusF.76Overheating protection on – primary heat exchanger has responded
VaillantEcoTEC Pro / EcoTEC PlusF.77Flue non return flap condensate pump error
VaillantEcoTEC Pro / EcoTEC PlusF.78Interruption to DHW outlet sensor at external controller
VaillantEcoTEC Pro / EcoTEC PlusF.83Flow and or return temperature sensor error
VaillantEcoTEC Pro / EcoTEC PlusF.84Error with flow/return temperature sensor temperature changing error
VaillantEcoTEC Pro / EcoTEC PlusF.85Error with flow and return temperature, sensor incorrectly fitted
VaillantEcoTEC Pro / EcoTEC PlusCONNECTIONNo communication with the PCB
Glow-wormBetacomRed LED onLockout – low water pressure (increase pressure to 1.5bar) and reset boiler
Glow-wormBetacomRed LED flashingOverheat – check both overheat stats
Glow-wormBetacomYellow LED flashingTurn domestic hot water (DHW) control knob into temperature range and turn central heating (CH) temperature control knob into power (reset position) and wait for minimum of 30 seconds before turning into either summer or temperature position.
Glow-wormBetacomYellow LED onFlame present on the burner
Glow-wormBetacomGreen LED onBoiler ready for operation
Glow-wormBetacomGreen LED offNo power to boiler – Check for 230volts into the appliance, check fuse on printed circuit board (PCB)
Glow-wormBetacom / Ultracom? cxi / sxi / 35F00 / F10 / F71Flow heating temperature sensor fault
Glow-wormBetacom / Ultracom? cxi / sxi / 35F01 / F11Return heating temperature sensor fault
Glow-wormBetacom / Ultracom? cxi / sxi / 35F20Overheating fault
Glow-wormBetacom / Ultracom? cxi / sxi / hxi / 35 / Flexicom cx / hx / sxF9 / F22Low water pressure (or ignition temperature rise too slow)
Glow-wormBetacom / Ultracom? cxi / sxi / 35F26 / F77Fault in gas valve
Glow-wormBetacom / Ultracom? cxi / sxi / 35 / CI / hxi / Xtramax HEF27 / F16Flame detection fault
Glow-wormAll BoilersF28 / F1 / F4Ignition fault (flame detection)
Glow-wormBetacom / Ultracom? cxi / sxi / 35F29Loss of flame during operation
Glow-wormBetacom / Ultracom? cxi / sxi / 35F32Incorrect air pressure
Glow-wormBetacom / Ultracom? cxi / sxi / 35F49EBUS voltage fault
Glow-wormBetacom / Ultracom? cxi / sxi / 35F61 / F62 / F63 / F64 / F65 / F67Fault in the main board
Glow-wormBetacom / Ultracom? cxi / sxi / 35F68Fluctuation of flame signal
Glow-wormBetacom / Ultracom? cxi / sxi / 35F70User interface incompatible with the main board
Glow-wormBetacom / Ultracom? cxi / sxi / 35F72 / F84Permanent temperature difference between flow and return heating sensors
Glow-wormBetacom / Ultracom? cxi / sxi / 35F73 / F74Heating circuit pressure sensor fault
Glow-wormBetacom / Ultracom? cxi / sxi / 35F76Thermal fuse fault
Glow-wormBetacom / Ultracom? cxi / sxi / 35F83Thermal fuse fault
Glow-wormBetacom / Ultracom? cxi / sxi / 35F85Flow and Return heating sensor fault
Glow-wormBetacom / Ultracom? cxi / sxi / 35F86Underfloor heating contact fault
Glow-wormAll BoilersERR / F12 / F18User interface fault
Glow-wormBetacom cTemperature 30 flashingFault on central heating (CH) thermistor
Glow-wormBetacom cTemperature 40 flashingFault on DHW thermistor
Glow-wormBetacom cTemperature 50 flashingFault on outside sensor
Glow-wormBetacom cTemperature 60 flashingLow system pressure
Glow-wormBetacom cTemperature 70 flashingFault on APS
Glow-wormBetacom cTemperature 80 flashingOverheat open circuit
Glow-wormBetacom cTemperature 90 flashingFlame or gas failure
Glow-wormCompact e / sNo DHWCheck dhw microswitch / Check external controls, Please test for 230V on switch live contact
Glow-wormCompact e / sNo C/HCheck dhw microswitch if dhw demand led is lit / Check external controls, Please test for 230V on switch live contact
Glow-wormCompact e / sNo C/H but boiler is firingCheck diverter motor and cartridge / Check external controls, Please test for 230V on switch live contact
Glow-wormCompact e / sBoiler locks out within 10 secondsCheck pump proving switch, air pressure switch and overheat state / Check pump proving switch, air pressure switch and overheat stat
Glow-wormCompact e / sPoor burner pressureCheck burner pressure/ignition adjustment pots on PCB
Glow-wormCi Range (plus) / Si rangeF2Fan/APS
Glow-wormAll BoilersF5Overheat Fault
Glow-wormAll BoilersF6Central heating flow thermistor
Glow-wormAll BoilersF7Domestic hot water thermistor
Glow-wormAll BoilersF8Tank thermistor fault
Glow-wormsxi / si / ci (plus) range / Xtramax HEF9Water pressure sensor fault (please contact GW technical department for further information)
Glow-wormAll boilersF10Central return flow thermistor
Glow-wormAll boilersF11Main board connection fault
Glow-wormCi (plus) / cxi / hxi / si / sxi rangeF12Connection fault between main printed circuit board (PCB) and display PCB
Glow-wormCi (plus) / cxi / hxi / si / sxi rangeF13Main PCB connection fault
Glow-wormCi (plus) / cxi / hxi / si / sxi rangeF14Central heating flow temperature > 95 degrees
Glow-wormCi (plus) / cxi / si / sxi rangeF15Gas valve stepper motor fault
Glow-wormCi (plus) / cxi / hxi / si / sxi range / Xtramax HEF17Power supply is less than 170v
Glow-wormCi (plus) / cxi / hxi / si / sxi range / Xtramax HEF19Central heating thermistor unplugged
Glow-wormCi (plus) / cxi / hxi / si / sxi range / Xtramax HEF20Software incompatibility
Glow-wormcxi / hxi / sxi range / Flexicom cxF24Central heating return temperature > 90 degrees
Glow-wormcxi / hxi / sxi / Xtrafast 96/120 / Xtrafast 96/120E1F25 / F26 / F11Poor circulation
Glow-wormci rangeF3Air fault
Glow-wormci rangeF3Air fault
Glow-wormcxi / sxi / hxi range/ Xtramax HEF2 / F3Fan
Glow-wormcxi / sxi range / Flexicom cx / hx / sx / hxi / Ultracom cxi / cx / hxi / sxi / Ultrapower sxiF3Fan unable to reach ignition speed
Glow-wormFlexicom cx / hx / sx / hxi / Ultracom cxi / cx / hxi / sxiF9Water pressure sensor fault, blocked flow filter or pump fault
Glow-wormFlexicom cx / hx / sxF11Flow and or return thermistor fault
Glow-wormFlexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi / Xtramax HEF13PCB memory or sensing fault
Glow-wormFlexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi / Xtramax HEF14Gas valve control defective
Glow-wormFlexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi / Xtramax HEF15E-bus voltage failure
Glow-wormAll boilersF25 / F23Circulation fault
Glow-wormFlexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxiF43Generic error
Glow-wormFlexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxiF70Software incompatible
Glow-wormFlexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxiF73Unable to see pump activate
Glow-wormFlexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxiF77Condensate pump error (optional)
Glow-wormhxi rangeF9Earlier models only (please contact GW technical department for further information)
Glow-wormhxi rangeF9Earlier models only (please contact GW technical department for further information)
Glow-wormUltracom? 35 StoreF02 / F12Hot water temperature sensor fault
Glow-wormUltracom? 35 StoreF03 / F13 / F79Storage tank temperature sensor fault
Glow-wormUltracom? 35 StoreF81Overheating of hot water circuit
Glow-wormAll UltracomNo display or Erloose connection X51
Glow-wormXtramax HE RangeF24Cental heating return temperature > 90 degrees
Glow-wormXtramax HE RangeF25Maximum temperature rise slope
Glow-wormXtramax HE RangeF26Maximum delta temperature
Glow-wormXtrafast 96/120 RangeF00No fault/td>
Glow-wormXtrafast 96/120 Range / Xtrafast 96/120E1 RangeF00No fault
Glow-wormXtrafast 96/120 Range / Xtrafast 96/120E1 RangeF02Air flow fault
Glow-wormXtrafast 96/120 Range / Xtrafast 96/120E1 RangeF05Overheating
Glow-wormXtrafast 96/120 Range / Xtrafast 96/120E1 RangeF06Central heating thermistor/wiring fault
Glow-wormXtrafast 96/120 Range / Xtrafast 96/120E1 RangeF08Storage vessel thermistor/wiring fault
Glow-wormXtrafast 96/120 Range / Xtrafast 96/120E1 RangeF09System pressure sensor fault
Glow-wormXtrafast 96/120 Range / Xtrafast 96/120E1 RangeF10Fan fault
Glow-wormXtrafast 96/120 Range / Xtrafast 96/120E1 RangeF13Main printed circuit board (PCB) fault
Glow-wormXtrafast 96/120 Range / Xtrafast 96/120E1 RangeF14Central heating flow temperature > 97 degrees
Glow-wormXtrafast 96/120 Range / Xtrafast 96/120E1 RangeF15Gas mechanism fault
Glow-wormXtrafast 96/120 Range / Xtrafast 96/120E1 RangeF20Communication fault
Glow-wormEnergyF.00Flow temperature sensor
Glow-wormEnergyF.10Flow temperature sensor short circuit
Glow-wormEnergyF.11Flow temperature sensor short circuit
Glow-wormEnergyF.12 and F.91Cylinder temperature sensor short circuit
Glow-wormEnergyF.13Domestic hot water cylinder temperature sensor short circuit
Glow-wormEnergyF.20Safety switch-off – overheating temperature reached
Glow-wormEnergyF.22Safety switch-off – low water pressure in the boiler
Glow-wormEnergyF.23Safety switch-off – temperature difference too great (NTC1/NTC2)
Glow-wormEnergyF.24Safety switch-off – temperature rise too fast
Glow-wormEnergyF.25Safety switch-off – flue gas temperature too high
Glow-wormEnergyF.27Safety switch-off – fault in flame detection
Glow-wormEnergyF.28Ignition unsuccessful when starting up
Glow-wormEnergyF.29Flame loss
Glow-wormEnergyF.32Fan frost protection function active – fan speed outside the tolerance values
Glow-wormEnergyF.33Fan frost protection function active – air pressure switch fault
Glow-wormEnergyFA9eBUS fault – voltage too low
Glow-wormEnergyF.61Gas valve control system fault
Glow-wormEnergyF.82Gas valve switch-off control fault
Glow-wormEnergyF.83EEPROM fault – electronics defective
Glow-wormEnergyF.64Electronics/sensor/analogue-to-digital converter fault
Glow-wormEnergyF.85Electronics temperature too high
Glow-wormEnergyF.67Value sent back by ASIC is incorrect (flame signal)
Glow-wormEnergyF.88Unstable flame (analogue input), underfloor heating contact or gas valve fault
Glow-wormEnergyF.70Invalid product code (DSN)
Glow-wormEnergyF.71Flow/return temperature sensor
Glow-wormEnergyF.72Deviation in the water pressure sensor/return temperature sensor
Glow-wormEnergyF.73Water pressure sensor not connected or has short-circuited
Glow-wormEnergyF.74Electrical problem in the water pressure sensor
Glow-wormEnergyF.75Pressure sensor fault
Glow-wormEnergyF.78The safety cut-out in the primary heat exchanger is defective
Glow-wormEnergyF.77Fault: Condensate or smoke
Glow-wormEnergyF.78Interruption to domestic hot water (DHW) outlet sensor at external controller
Glow-wormEnergyF.83Burner temperature sensor fault
Glow-wormEnergyF.84Flow/return temperature sensor fault
Glow-wormEnergyF.85Temperature sensor fault
Glow-wormEnergyF.87Electrodes fault
Glow-wormEnergyF.89Pump fault
Glow-wormEnergyConnectionNo communication between the printed circuit board (PCB) and the user interface
IdealLogicL1Flow temperature overheat lockout or no water flow lockout
IdealLogicL2Ignition lockout
IdealLogicLC5 restarts within 15 minutes
IdealLogicL6False flame lockout
IdealLogicFAFlow return reversed
IdealLogicFDNo water flow
IdealLogicF2 or FN or LNFlame loss
IdealLogicF3Fan fault
IdealLogicL4 or F4Control / no flow thermistor fault
IdealLogicL5 or F5Return thermistor fault
IdealLogicF6Outside sensor fault
IdealLogicF7Low mains voltage Contact electricity provider
IdealLogicF9, L9, F8 or L8Printed circuit board (PCB) unconfigured or fault
IdealLogicFUDiff greater than 50c check isolation valves are open
IdealBoilers except LogicC0Boiler chip card (BCC) activation fault
IdealBoilers except LogicC2Boiler chip card (BCC) fault
IdealBoilers except LogicF1Low water pressure
IdealBoilers except LogicF2Flame loss
IdealBoilers except LogicF3Fan fault
IdealBoilers except LogicF4Flow thermistor fault
IdealBoilers except LogicF5Return thermistor fault
IdealBoilers except LogicF6Outside sensor failure
IdealBoilers except LogicF7Low mains voltage
IdealBoilers except LogicF9Un-configured printed circuit board (PCB)
IdealBoilers except LogicL1Flow temperature overheat or no water flow
IdealBoilers except LogicL2Flame loss
IdealBoilers except LogicL55 boiler resets in 15 minutes
IdealBoilers except LogicL6False flame lockout
IdealBoilers except LogicFault CodeSystem Behaviour
IdealBoilers except Logic0The boiler is in standby mode awaiting either a central heating call or hot water demand
IdealBoilers except LogicCThe boiler has a call for central heating but the appliance has reached the desired temperature set on the boiler
IdealBoilers except LogicDThe boiler has a call for hot water but the appliance has reached the desired temperature set on the boiler
IdealBoilers except LogicCThe boiler is operating in central heating mode
IdealBoilers except LogicdThe boiler is operating in hot water mode
IdealBoilers except LogicFThe boiler is operating in frost mode
BaxiPlatinumE20Central heating NTC error
BaxiPlatinumE28Error with the NTC flue. Possible air pressure switch error. Blocked flue or condensate or wing fault
BaxiPlatinumE50Hot water NTC error
BaxiPlatinumE110Thermostat operated safety
BaxiPlatinumE119Water pressure switch error – Not operated.
BaxiPlatinumE125Primary circuit error circulation fault
BaxiPlatinumE130FLue NTC Operation error
BaxiPlatinumE133Gas supply Error or flame failure
BaxiPlatinumE160Fan Error / Fan Wiring Error
BaxiPlatinumE193Pre-circulation error
BaxiEcoBlue110Overheated – try bleeding your radiators
BaxiEcoBlue117Water pressure too high
BaxiEcoBlue118Water pressure too low
BaxiEcoBlue125Water circulation fault
BaxiEcoBlue133Safety time to establish flame exceeded
BaxiEcoBlueE10Outdoor sensor error
BaxiEcoBlueE20Central heating thermistor sensor fault
BaxiEcoBlueE28Flue thermistor fault
BaxiEcoBlueE54Domestic hot water (DHW) flow sensor fault
BaxiEcoBlueE78Water pressure sensor fault
BaxiEcoBlueE100Internal clock time error on printed circuit board (PCB)
BaxiEcoBlueE109Poor circulation
BaxiEcoBlue110Overheat – try bleeding your radiators
BaxiEcoBlue111Maximum limit of flow temperature
BaxiEcoBlue117Water pressure too high
BaxiEcoBlue118Water pressure too low
BaxiEcoBlue119System pressure too low
BaxiEcoBlue125Water circulation fault
BaxiEcoBlue127Legionella (cause of Legionnaires’ disease) protection temperature not reached
BaxiEcoBlue128Loss of flame during operation
BaxiEcoBlue133Safety time to establish flame exceeded
BaxiEcoBlue153Forced reset unit unlocked
BaxiEcoBlue160Fan fault
BaxiEcoBlue162Air pressure switch error
BaxiEcoBlue164Pressure Sensor Error (UK) – Heating flow switch error (Ireland)
BaxiEcoBlue166Air pressure switch fault
BaxiEcoBlue270Dry fire
BaxiEcoBlue432Earth connector error
BaxiEcoBlue433Heat exchanger temperature exceeded (greater than 95 degrees)
BaxiEcoBlue Advance1 green flashBoiler temperature reached. No action required.
BaxiEcoBlue Advance3 green flashesTemporary flame loss. Boiler will self reset, if fault continues you will see 3 red flashes.
BaxiEcoBlue Advance4 green flashesCommunication error between printed circuit board (PCB) and control. Temporary error, will self reset.
BaxiEcoBlue Advance5 green flashesParameter error on printed circuit board (PCB). Temporary error, will self reset
BaxiEcoBlue Advance6 green flashesMiscellaneous error. Temporary error, will self reset.
BaxiEcoBlue Advance1 red flashSensor error, temperature fault or flow fault.
BaxiEcoBlue Advance2 red flashesBoiler overheat tripped
BaxiEcoBlue Advance3 red flashesIgnition fault. Boiler has attempted to light 5 times and failed.
BaxiEcoBlue Advance4 red flashesFan fault
BaxiEcoBlue Advance5 red flashesParameter storage unit (PSU) error.
BaxiEcoBlue Advance6 red flashesMiscellaneous error.
BaxiDuo-tec/MegafloE10Outdoor sensor fault
BaxiDuo-tec/MegafloE20Central heating thermistor sensor error
BaxiDuo-tec/MegafloE28Flue thermistor error
BaxiDuo-tec/MegafloE110Boiler overheat error
BaxiDuo-tec/MegafloE119Low water pressure error
BaxiDuo-tec/MegafloE125Primary water circulation error
BaxiDuo-tec/MegafloE131Flue overheat lockout error
BaxiDuo-tec/MegafloE133Ignition error
BaxiDuo-tec/MegafloE160 / E161Fan error
BaxiDuo-tec/MegafloE164Pressure sensor fault
BaxiDuo-tec/MegafloE167Printed circuit board (PCB) error
BaxiDuo-tec/MegafloE168Printed circuit board (PCB) lockout error
BaxiDuo-tec/MegafloE193Circulation error
Baxi200 / 400 H.01 – .00Loss of communication between gas valve and boiler board. Possible fault in air/gas unit or loose connection to gas valve.
Baxi200 / 400 H.01 – .05Difference between the flow and return temperature is too high, sensor error or insufficient circulation.
Baxi200 / 400 H.01 – .08Sensor fault, flow temperature increasing too fast in heating mode or insufficient circulation.
Baxi200 / 400 H.01 – .14Maximum flow temperature value exceeded or insufficient circulation – temporary fault.
Baxi200 / 400 H.01 – .18No water circulation, insufficient circulation or sensor error.
Baxi200 / 400 H.01 – .21Temporary error – flow temperature increasing too fast in domestic hot water (DHW) mode, insufficient circulation or sensor error.
Baxi200 / 400 H.02 – .02Temporary error – no input of parameters C1/C2. Printed circuit board (PCB) not configured.
Baxi200 / 400 H.02 – .03Temporary error- incorrect configuration settings C1/C2.
Baxi200 / 400 H.02 – .04Temporary error- parameter fault. Incorrect parameters.
Baxi200 / 400 H.02 – .06Temporary error caused by system water pressure, water leak on boiler, water leak on system.
Baxi200 / 400 H.03 -.00Temporary error with communication, negative temperature coefficient thermostat (NTC)
Baxi200 / 400 H.03 – .01Communication error with the printed circuit board (PCB)
Baxi200 / 400 H.03 – .02Flame error – no flame during operation.
Baxi200 / 400 E.00 – .04Return temperature sensor open-circuit. Sensor not or badly connected.
Baxi200 / 400 E.00 – .05Return temperature sensor short-circuit. Sensor not connected or badly connected.
Baxi200 / 400 E.01 – .02Temperature measured by return sensor greater than flow sensor.
Baxi200 / 400 E.01 – .04Loss of flame detected 5 times in 24 hours (with burner on).
Baxi200 / 400 E.01 – .11Incorrect fan speed – external draught over the boiler or defective gas/air unit.
Baxi200 / 400 E.01 – .12Requires reset – temperature measured by return sensor greater than flow temperature.
Baxi200 / 400 E.01 – .17Reset the boiler – no circulation, sensor fault either not connected or has a bad connection.
Baxi200 / 400 E.01 – .20Maximum flue gas temperature reached. No circulation or sensor fault.
Baxi200 / 400 E.02 – .00Reset button has been pressed.
Baxi200 / 400 E.02 – .07No or low system water pressure. system pressure less than 0.5bar
Baxi200 / 400 E.02 – .16Permanent fault caused by channel service unit (CSU) time-out or printed circuit board (PCB) damage.
Baxi200 / 400 E.02 – .17Loss of communication between gas valve and boiler printed circuit board (PCB) or fault in air/gas unit.
Baxi200 / 400 E.02 – .19Jumper 1 changed – check position of jumper 1.
Baxi200 / 400 E.02 – .20Jumper 2 changed – check position of jumper 2.
Baxi200 / 400 E.02 – .21Jumper 3 changed – check position of jumper 3.
Baxi200 / 400 E.02 – .47Wiring to external device error.
Baxi200 / 400 E.02 – .48Configuration to external device unsuccessful – check pairing to external device.
Baxi200 / 400 E.04 – .00Gas valve error – gas valve not detected.
Baxi200 / 400 E.04 – .01Flow temperature sensor short-circuited. Sensor not or badly connected, bad connection or sensor fault.
Baxi200 / 400 E.04 – .02Permanent fault. Flow temperature sensor open-circuited, sensor not or badly connected, bad connection or sensor fault.
Baxi200 / 400 E.04 – .03Permanent fault. Critical flow temperature reached, non-existent or insufficient circulation.
Baxi200 / 400 E.04 – .04Permanent fault. Flue temperature sensor short-circuited, sensor not or badly connected, bad connection or sensor fault.
Baxi200 / 400 E.04 – .05Permanent fault. Flue temperature sensor short-circuited, sensor not or badly connected, bad connection or sensor fault.
Baxi200 / 400 E.04 – .06Permanent fault. Critical flue gas temperature value reached, no circulation or sensor fault.
Baxi200 / 400 E.04 – .08Permanent fault. Maximum safe temperature value reached, safety thermostat open-circuited, no circulation, sensor not or badly connected, bad connection or sensor fault.
Baxi200 / 400 E.04 – .10Failure to light (could be gas supply issue).
Baxi200 / 400 E.04 – .12Permanent fault. False flame signal, short-term fluctuation of the mains, ionisation current present even though there is no flame, the burner remains very hot (CO2 too high) or defective gas/air unit.
Baxi200 / 400 E.04 – .13Permanent fault. Fan rotor blocked, fan seized or wiring to fan damaged.
Baxi200 / 400 E.04 – .17Permanent fault. Problem with gas valve or defective gas/air unit.
Baxi600E09Gas valve connection cable.
Baxi600E10External probe fault.
Baxi600E12Differential water flow switch fault (still open).
Baxi600E13Differential water flow switch fault (still closed).
Baxi600E15Gas valve command fault.
Baxi600E20Central heating negative temperature coefficient (NTC) thermostat fault.
Baxi600E28Flue negative temperature coefficient (NTC) thermostat fault.
Baxi600E40Central heating return negative temperature coefficient (NTC) thermostat fault.
Baxi600E50Domestic hot water (DHW) negative temperature coefficient (NTC) thermostat sensor fault (tank boiler) (s.c.) or DHW NTC sensor fault (tank boiler) (o.c.).
Baxi600E83/E84/E85/E86/E87No communication.
Baxi600E109Pre-circulation fault.
Baxi600E110Boiler max temperature exceeded for gradient (probable pump jammed or air in the circuit Boiler max temperature exceeded for over temperature (probable pump jammed or air in the circuit Safety thermostat sensor tripped.
Baxi600E118Primary system water pressure too low (< 0.5 bar).
Baxi600E125Circulation fault (primary).
Baxi600E128Frequent flame failure (12 times).
Baxi600E129Safety error for frequently loss of flame with max correction during the ignition during Calibration Function.
Baxi600E130Flue thermostat sensor tripped (lockout).
Baxi600E133Failure to light (could be a gas supply issue).
Baxi600E134Elapsed time gas valve open without gas (short request in a short period)
Baxi600E135Interruption of gas supply (internal error).
Baxi600E154Flow/return sensor temperature test.
Baxi600E160Fan or fan wiring fault.
Baxi600E163Domestic hot water (DHW) negative temperature coefficient (NTC) thermostat sensor fault (s.c.) or DHW NTC sensor fault (o.c.).
Baxi600E270Circulation fault (dry fire).
Baxi600E317Wrong power supply electrical frequency (Hz).
Baxi600E321Hot water negative temperature coefficient (NTC) fault.
Baxi600E384False flame.
Baxi600E385Under voltage.
Baxi600E430Water pressure temporary test.
Baxi600E430 + Flame ‘crossed’Water pressure test failed.
BaxiMainEco1 Green FlashBoiler temperature reached – no action required
BaxiMainEco3 Green FlashesTemporary flame loss – this is a temporary error, the system should reset on its own
BaxiMainEco4 Green FlashesCommunication error between printed circuit board (PCB) and Control – this is a temporary error, the system should reset on its own
BaxiMainEco5 Green FlashesParameter error on parameter storage unit (PSU) or printed circuit board (PCB) – this is a temporary error, the system should reset on its own.
BaxiMainEco6 Green FlashesMiscellaneous error
BaxiMainEco1 Red FlashSensor error, sensor fault, temperature fault or flow fault – this is a temporary error, the system should reset on it’s own.
BaxiMainEco2 Red FlashesBoiler overheat tripped
BaxiMainEco3 Red FlashesIgnition fault. Boiler has attempted to light 5 times and failed
BaxiMainEco4 Red FlashesFan Fault
BaxiMainEco5 Red FlashesParameter storage unit (PSU) error
BaxiMainEco6 Red FlashesMiscellaneous
BaxiAvantaE0Temperature sensor fault
BaxiAvantaE1Overheated – try bleeding your radiators
BaxiAvantaE2Poor circulation – try bleeding your radiators
BaxiAvantaE3Printed circuit board (PCB) fault
BaxiAvantaE4Ignition failure – try bleeding your radiators
BaxiAvantaE10Poor/No circulation
BaxiAvantaE12Printed circuit board (PCB) Fault
BaxiAvantaE13Heat exchanger thermal fuse tripped
BaxiAvantaE83 / 84 / 85 / 86 / 87Fan fault normally E8
BaxiGA RangeE53Poor combustion – flue terminal may be blocked
BaxiGA RangeE110Overheated – try bleeding your radiators
BaxiGA RangeE117System water pressure high – try bleeding water from your radiators
BaxiGA RangeE118System water pressure low
BaxiGA RangeE125Overheat – try bleeding your radiators
BaxiGA RangeE133Gas supply fault
BaxiGA RangeE4Ignition failure
BaxiGA RangeE09Gas valve wiring fault
BaxiGA RangeE10Outdoor sensor error
BaxiGA RangeE15Gas valve connection fault
BaxiGA RangeE20Central heating thermistor sensor fault
BaxiGA RangeE28Flue thermistor fault
BaxiGA RangeE40Central heating return thermistor fault
BaxiGA RangeE53Flue obstruction
BaxiGA RangeE55Calibration required
BaxiGA RangeE78Water pressure sensor fault
BaxiGA RangeE92Combustion test alarm during auto-setting
BaxiGA RangeE109Poor circulation
BaxiGA RangeE110Boiler overheat tripped
BaxiGA RangeE117System pressure high (>2.9 Bar)
BaxiGA RangeE118System pressure low(< 0.5bar)
BaxiGA RangeE125Primary water circulation fault
BaxiGA RangeE128Loss of flame during operation
BaxiGA RangeE129Loss of flame during calibration
BaxiGA RangeE133Ignition fault
BaxiGA RangeE135Internal error
BaxiGA RangeE154Primary flow fault
BaxiGA RangeE160Fan fault
BaxiGA RangeE270Dry fire
BaxiGA RangeE317Wrong power supply (Hz)
BaxiGA RangeE321Not water thermistor fault
BaxiGA RangeE384Flame detected when gas valve off
BaxiGA RangeE385Low voltage (less than 195v)
BaxiSoloFLASH FLASH ONFan error
BaxiSoloFLASH OFF FLASHVoltage less than 180V
BaxiSoloFLASH OFF ONOverheat lockout
BaxiSoloFLASH ON FLASHPrinted circuit board (PCB) error
BaxiSoloFLASH ON ONPrinted circuit board (PCB) fault
BaxiSoloOFF OFF OFFNo power
BaxiSoloON FLASH FLASHCirculation error or dry fire
BaxiSoloON FLASH ONThermistor error
BaxiSoloON OFF FLASHLive and neutral reversed error
BaxiSoloON OFF ONIgnition lockout error
BaxiSoloON ON FLASHPrinted circuit board (PCB) error
BaxiSoloON ON ONLow voltage wiring harness error
FerroliiBoilerA01Ignition error – possible electrode fault or power too low, no gas or excessive condensate level
FerroliiBoilerA02Electrode or card error
FerroliiBoilerA03Heating sensor damaged, no water circulation or air in system
FerroliiBoilerF04Wrong card parameter setting
FerroliiBoilerF05Air pressure switch contact error – wrong flue baffle obstructed or not correctly sized
FerroliiBoilerA06No flame after the ignition phase – low pressure in gas system burner minimum pressure setting
FerroliiBoilerF07Air pressure switch error – contacts closed on activation of fan
FerroliiBoilerA09Gas valve error – wiring could be disconnected or error with gas valve
FerroliiBoilerF10Delivery sensor error, sensor damaged wiring shorted or disconnected
FerroliiBoilerF11Domestic hot water (DHW) sensor error – sensor damaged, wiring shorted or disconnected
FerroliiBoilerA15Fault F05 generated 5 times within the last 24 hours – possible error with the air pressure switch
FerroliiBoilerA16Gas valve error – wiring disconnected or faulty gas valve
FerroliiBoilerA23Card parameter error – possibly wrong card parameter setting
FerroliiBoilerA24Card parameter error – possibly wrong card parameter setting
FerroliiBoilerF34Supply voltage under 170V – electric mains error
FerroliiBoilerF35Faulty mains frequency – electric mains error
FerroliiBoilerF37Error with system water pressure, possible pressure too low or water pressure switch is damaged
FerroliiBoilerF43Exchanger protection intervention – could be because no system water circulation or there’s air in the system
FerroliiBoilerF50Controller DBM23B error – controller could have an internal error
FerroliiBoilerF51Controller DBM23B error – controller could have an internal error
FerroliModena HEA01No burner ignition – possibly no gas, detection or ignition electrode fault, defective gas valve, incorrect inlet gas pressure
FerroliModena HEA02Flame detected with the burner off – possibly caused by ionisation, defective electrode or main board defective. Check the printed circuit board (PCB) or ionizing electrode wiring
FerroliModena HEA03High limit protection – flow temperature sensor not active, incorrectly located or no system circulation. Check the position of the flow sensor or check pump and radiator valves
FerroliModena HEA04Flue gas fault – could be because F07 happened 3 times in the last 24 hours – check the flue
FerroliModena HEA05Fan problem – tachometer signal interrupted for 1 hour or longer – check the wiring and the fan
FerroliModena HEA06No flame after ignition phase – possible causes: detection electrode fault, flame unstable, incorrect valve gas offset, flue gas circuit
FerroliModena HEA41Flow sensor disconnected – check the correct positioning and operation of the flow sensors
FerroliModena HEA42Flow sensor fault – sensor needs changing
FerroliModena HEF07High fume temperature – the exchanger probe detects an excessive temperature for over 2 minutes – check the exchanger.
FerroliModena HEF10Flow sensor fault – possible causes: sensor damaged, short circuited or wiring broken check the wiring
FerroliModena HEF11Return sensor fault – sensor wiring shorted or broken – check the wiring
FerroliModena HEF12Domestic hot water (DHW) sensor fault – sensor damaged, wiring shorted or wiring disconnected – check the wiring
FerroliModena HEF13Exchange probe fault – wiring shorted or wiring broken – check wiring
FerroliModena HEF14Fan problem – tachometer signal interrupted fan connection. Fan damaged or debris in fan – check the wiring, the fan and clean debris
FerroliModena HEF15Supply voltage under 170v – electric supply problem – the electrical system needs checking
FerroliModena HEF34Irregular mains frequency – possible electric supply problem – the electrical system needs checking
FerroliModena HEF35Incorrect system water pressure – possible cause is pressure too low or sensor damaged –
FerroliModena HEF37External probe fault sensor damaged or short circuited – check the wiring
FerroliModena HEF39Exchanger protection activation – possibly caused by no system circulation, air in the system or sensor damaged
FerroliModena HEF43Flow sensor fault – sensor damaged – sensor needs changing
FerroliModena HEF52Controller 041049G0 fault – controller internal error
FerroliModena HEA61No communication between controller and gas valve controller – could not be connected or valve damaged
FerroliModena HEA62Controller 041049G – internal error
FerroliModena HEA63 / A64 / F66Controller DBM12 fault