Baxi
Fault Codes

Listed below are the common Baxi fault codes as described by the boiler manufacturer along with a possible cause.

Baxi Platinum Error Codes

Fault Code	Possible Cause
E20	Central heating NTC error
E28	Error with the NTC (Negative Temperature Coefficient) flue, air pressure switch or blocked flue or condensate
E50	Hot water NTC (Negative Temperature Coefficient) error
E110	Thermostat operated safety
E119	Water pressure switch error – not operated.
E125	Primary circuit error circulation fault
E130	Flue NTC (Negative Temperature Coefficient) operation error
E133	Gas supply error or flame failure
E160	Fan or fan wiring error
E193	Pre-circulation error

Baxi EcoBlue Error Codes

Fault Code	Possible Cause
110	Overheated – try bleeding your radiators
117	Water pressure too high
118	Water pressure too low
125	Water circulation fault
133	Safety time to establish flame exceeded
E10	Outdoor sensor error
E20	Central heating thermistor sensor fault
E28	Flue thermistor fault
E54	Domestic hot water (DHW) flow sensor fault
E78	Water pressure sensor fault
E100	Internal clock time error on printed circuit board (PCB)
E109	Poor circulation
110	Overheat – try bleeding your radiators
111	Maximum limit of flow temperature
117	Water pressure too high
118	Water pressure too low
119	System pressure too low
125	Water circulation fault
127	Legionella (cause of Legionnaires’ disease) protection temperature not reached
128	Loss of flame during operation
133	Safety time to establish flame exceeded
153	Forced reset unit unlocked
160	Fan fault
162	Air pressure switch error
164	Pressure Sensor Error (UK) – Heating flow switch error (Ireland)
166	Air pressure switch fault
270	Dry fire
432	Earth connector error
433	Heat exchanger temperature exceeded (greater than 95 degrees)

EcoBlue Advance / Ecoblue Regular Gas Boiler Flashing Light Fault Codes

Fault Code	Possible Cause
1 green flash	Boiler temperature reached. No action required.
3 green flashes	Temporary flame loss. Boiler will self reset, if fault continues you will see 3 red flashes.
4 green flashes	Communication error between printed circuit board (PCB) and control. Temporary error, will self reset.
5 green flashes	Parameter error on printed circuit board (PCB). Temporary error, will self reset
6 green flashes	Miscellaneous error. Temporary error, will self reset.
1 red flash	Sensor error, temperature fault or flow fault.
2 red flashes	Boiler overheat tripped
3 red flashes	Ignition fault. Boiler has attempted to light 5 times and failed.
4 red flashes	Fan fault
5 red flashes	Parameter storage unit (PSU) error.
6 red flashes	Miscellaneous error.

Baxi Duo-tec/Megaflo Error Codes

Fault Code	Possible Cause
E10	Outdoor sensor fault
E20	Central heating thermistor sensor error
E28	Flue thermistor error
E110	Boiler overheat error
E119	low water pressure error
E125	Primary water circulation error
E131	Flue overheat lockout error
E133	Ignition error
E160 / E161	Fan error
E164	Pressure sensor fault
E167	Printed circuit board (PCB) error
E168	Printed circuit board (PCB) lockout error
E193	Circulation error

Baxi 200 / 400 Combi Gas Boiler Error Codes

Fault Code	Possible Cause
H.01 – .00	Loss of communication between gas valve and boiler board. Possible fault in air/gas unit or loose connection to gas valve.
H.01 – .05	Difference between the flow and return temperature is too high, sensor error or insufficient circulation.
H.01 – .08	Sensor fault, flow temperature increasing too fast in heating mode or insufficient circulation.
H.01 – .14	Maximum flow temperature value exceeded or insufficient circulation – temporary fault.
H.01 – .18	No water circulation, insufficient circulation or sensor error.
H.01 – .21	Temporary error – flow temperature increasing too fast in domestic hot water (DHW) mode, insufficient circulation or sensor error.
H.02 – .02	Temporary error – no input of parameters C1/C2. Printed circuit board (PCB) not configured.
H.02 – .03	Temporary error- incorrect configuration settings C1/C2.
H.02 – .04	Temporary error- parameter fault. Incorrect parameters.
H.02 – .06	Temporary error caused by system water pressure, water leak on boiler, water leak on system.
H.03 -.00	Temporary error with communication, negative temperature coefficient thermostat (NTC) or flue sensor. Sensor could also be unconnected or have a bad connection.
H.03 – .01	Communication error with the printed circuit board (PCB)
H.03 – .02	Flame error – no flame during operation.
E.00 – .04	Return temperature sensor open-circuit. Sensor not or badly connected.
E.00 – .05	Return temperature sensor short-circuit. Sensor not connected or badly connected.
E.01 – .02	Temperature measured by return sensor greater than flow sensor.
E.01 – .04	Loss of flame detected 5 times in 24 hours (with burner on).
E.01 – .11	Incorrect fan speed – external draught over the boiler or defective gas/air unit.
E.01 – .12	Requires reset – temperature measured by return sensor greater than flow temperature.
E.01 – .17	Reset the boiler – no circulation, sensor fault either not connected or has a bad connection.
E.01 – .20	Maximum flue gas temperature reached. No circulation or sensor fault.
E.02 – .00	Reset button has been pressed.
E.02 – .07	No or low system water pressure. system pressure less than 0.5bar
E.02 – .16	Permanent fault caused by channel service unit (CSU) time-out or printed circuit board (PCB) damage.
E.02 – .17	Loss of communication between gas valve and boiler printed circuit board (PCB) or fault in air/gas unit.
E.02 – .19	Jumper 1 changed – check position of jumper 1.
E.02 – .20	Jumper 2 changed – check position of jumper 2.
E.02 – .21	Jumper 3 changed – check position of jumper 3.
E.02 – .47	Wiring to external device error.
E.02 – .48	Configuration to external device unsuccessful – check pairing to external device.
E.04 – .00	Gas valve error – gas valve not detected.
E.04 – .01	Flow temperature sensor short-circuited. Sensor not or badly connected, bad connection or sensor fault.
E.04 – .02	Permanent fault. Flow temperature sensor open-circuited, sensor not or badly connected, bad connection or sensor fault.
E.04 – .03	Permanent fault. Critical flow temperature reached, non-existent or insufficient circulation.
E.04 – .04	Permanent fault. Flue temperature sensor short-circuited, sensor not or badly connected, bad connection or sensor fault.
E.04 – .05	Permanent fault. Flue temperature sensor short-circuited, sensor not or badly connected, bad connection or sensor fault.
E.04 – .06	Permanent fault. Critical flue gas temperature value reached, no circulation or sensor fault.
E.04 – .08	Permanent fault. Maximum safe temperature value reached, safety thermostat open-circuited, no circulation, sensor not or badly connected, bad connection or sensor fault.
E.04 – .10	Failure to light (could be gas supply issue).
E.04 – .12	Permanent fault. False flame signal, short-term fluctuation of the mains, ionization current present even though there is no flame, the burner remains very hot (CO2 too high) or defective gas/air unit.
E.04 – .13	Permanent fault. Fan rotor blocked, fan seized or wiring to fan damaged.
E.04 – .17	Permanent fault. Problem with gas valve or defective gas/air unit.

Baxi 600 Combi Gas Boiler Error Codes

Fault Code	Possible Cause
E09	Gas valve connection cable.
E10	External probe fault.
E12	Differential water flow switch fault (still open).
E13	Differential water flow switch fault (still closed).
E15	Gas valve command fault.
E20	Central heating negative temperature coefficient (NTC) thermostat fault.
E28	Flue negative temperature coefficient (NTC) thermostat fault.
E40	Central heating return negative temperature coefficient (NTC) thermostat fault.
E50	Domestic hot water (DHW) negative temperature coefficient (NTC) thermostat sensor fault (tank boiler) (s.c.) or DHW NTC sensor fault (tank boiler) (o.c.).
E83/E84/E85/E86/E87	No communication.
E109	Pre-circulation fault.
E110	Boiler max temperature exceeded for gradient (probable pump jammed or air in the circuit Boiler max temperature exceeded for overtemperature (probable pump jammed or air in the circuit Safety thermostat sensor tripped.
E118	Primary system water pressure too low (< 0.5 bar).
E125	Circulation fault (primary).
E128	Frequent flame failure (12 times).
E129	Safety error for frequently loss of flame with max correction during the ignition during Calibration Function.
E130	Flue thermostat sensor tripped (lockout)
E133	Failure to light (could be a gas supply issue)
E134	Elapsed time gas valve open without gas (short request in a short period)
E135	Interruption of gas supply (internal error)
E154	Flow/return sensor temperature test.
E160	Fan or fan wiring fault.
E163	Domestic hot water (DHW) negative temperature coefficient (NTC) thermostat sensor fault (s.c.) or DHW NTC sensor fault (o.c.).
E270	Circulation fault (dry fire).
E317	Wrong power supply electrical frequency (Hz).
E321	Hot water negative temperature coefficient (NTC) fault.
E384	False flame.
E385	Under voltage.
E430	Water pressure temporary test.
E430 + Flame ‘crossed’	Water pressure test failed.

Baxi MainEco Error Codes

Fault Code	Possible Cause
1 Green Flash	Boiler temperature reached – no action required
3 Green Flashes	Temporary flame loss – this is a temporary error, the system should reset on its own
4 Green Flashes	Communication error between printed circuit board (PCB) and Control – this is a temporary error, the system should reset on its own
5 Green Flashes	Parameter error on parameter storage unit (PSU) or printed circuit board (PCB) – this is a temporary error, the system should reset on its own.
6 Green Flashes	Miscellaneous error
1 Red Flash	Sensor error, sensor fault, temperature fault or flow fault – this is a temporary error, the system should reset on it’s own.
2 Red Flashes	Boiler overheat tripped
3 Red Flashes	Ignition fault. Boiler has attempted to light 5 times and failed
4 Red Flashes	Fan Fault
5 Red Flashes	Parameter storage unit (PSU) error
6 Red Flashes	Miscellaneous

Baxi Avanta Range Error Codes

Fault Code	Possible Cause
E0	Temperature sensor fault
E1	Overheated – try bleeding your radiators
E2	Poor circulation – try bleeding your radiators
E3	Printed circuit board (PCB) fault
E4	Ignition failure – try bleeding your radiators
E10	Poor/No circulation
E12	Printed circuit board (PCB) Fault
E13	Heat exchanger thermal fuse tripped
E83 / 84 / 85 / 86 / 87	Fan fault normally E8

Baxi GA Range Error Codes

Fault Code	Possible Cause
E53	Poor combustion – flue terminal may be blocked
E110	Overheated – try bleeding your radiators
E117	System water pressure high – try bleeding water from your radiators
E118	System water pressure low
E125	Overheat – try bleeding your radiators
E133	Gas supply fault
E4	Ignition failure
E09	Gas valve wiring fault
E10	Outdoor sensor error
E15	Gas valve connection fault
E20	Central heating thermistor sensor fault
E28	Flue thermistor fault
E40	Central heating return thermistor fault
E53	Flue obstruction
E55	Calibration required
E78	Water pressure sensor fault
E92	Combustion test alarm during auto-setting
E109	Poor circulation
E110	Boiler overheat tripped
E117	System pressure high (>2.9 Bar)
E118	System pressure low(< 0.5bar)
E125	Primary water circulation fault
E128	Loss of flame during operation
E129	Loss of flame during calibration
E133	Ignition fault
E135	Internal error
E154	Primary flow fault
E160	Fan fault
E270	Dry fire
E317	Wrong power supply (Hz)
E321	Not water thermistor fault
E384	Flame detected when gas valve off
E385	Low voltage (less than 195v)

Baxi Solo Error Codes

Fault Code	Possible Cause
FLASH FLASH ON	Fan error
FLASH OFF FLASH	Voltage less than 180V
FLASH OFF ON	Overheat lockout
FLASH ON FLASH	Printed circuit board (PCB) error
FLASH ON ON	Printed circuit board (PCB) fault
OFF OFF OFF	No power
ON FLASH FLASH	Circulation error or dry fire
ON FLASH ON	Thermistor error
ON OFF FLASH	Live and neutral reversed error
ON OFF ON	Ignition lockout error
ON ON FLASH	Printed circuit board (PCB) error
ON ON ON	Low voltage wiring harness error

Error Code E133 and E28

If you’re seeing either of these two error codes on your Baxi boiler, this is due to your condensate pipe being frozen. In the cold winter months this can happen easily as the condensate pipe runs outside. You can fix this issue by thawing out the pipe (if you feel confident to).

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BaxiFault Codes