Baxi Boiler Error Codes / Fault Codes List

Error Code

Possible Fault

H.01 – .00

Temporary Fault – Temporary loss of communication between the gas valve and boiler board. Fault in air/gas unit.

Loose connection to the gas valve.

H.01 – .05

Temporary Fault – Maximum difference between the flow and return temperature exceeded. Non-existent or insufficient circulation. Sensor error.

H.01 – .08

Temporary Fault – Flow temperature increasing too fast in heating mode. Non-existent or insufficient circulation.
Sensor error.

H.01 – .14

Temporary Fault – Maximum flow temperature value exceeded. Non-existent or insufficient circulation. Non-existent or insufficient circulation.

H.01 – .18

Temporary Fault – No circulation of water. Non-existent or insufficient circulation. Sensor error.

H.01 – .21

Temporary Fault – Flow temperature increasing too fast in DHW mode. Non-existent or insufficient circulation. Sensor error.

H.02 – .02

Temporary Fault – No input of parameters C1/C2. PCB not configured.

H.02 – .03

Temporary Fault– Incorrect configuration settings C1/C2.

H.02 – .04

Temporary Fault – Parameter error. Incorrect parameters.

H.02 – .06

Temporary Fault – System water pressure. Water leak on the boiler. Water leak on the system.

H.03 -.00

Temporary Fault – Communication error with NTC flue sensor. Sensor not, or badly connected. Bad connection. Sensor fault.

H.03 -.01

Temporary Fault – Communication error with the HMI PCB. HMI is not connected.

H.03 -.02

Temporary Fault – No flame during operation. No ionization current.

E.00 – .04

Permanent Fault – Return temperature sensor open-circuit. Sensor not or badly connected. Bad connection. Sensor fault.

E.00 – .05

Permanent Fault – Return temperature sensor open-circuit. Sensor not or badly connected. Bad connection. Sensor fault.

E.01 – .02

Permanent Fault – Temperature measured by return sensor greater than flow sensor. Bad connection. Sensor fault. Sensor not or badly connected.

E.01 – .04

Permanent Fault – Loss of flame detected 5 times in 24 hours (With burner on). No ionization current.

E.01 – .11

Permanent Fault Requiring Reset – Incorrect fan speed. External draught over the boiler. Defective gas/air unit.

E.01 – .12

Permanent Fault Requiring Reset – Temperature measured by return sensor greater than flow temperature.

E.01 – .17

Permanent Fault Requiring Reset – No circulation. Sensor not or badly connected. Sensor fault.

E.01 – .20

Permanent Fault – Maximum flue gas temperature value reached (>140 Deg C). No circulation. Sensor fault.

E.02 – .00

Permanent Fault – Boiler reset in progress. Reset button has been pressed.

E.02 – .07

No or low system water pressure. Low system pressure (less than 0.5bar) boiler will not function.

E.02 – .16

Permanent Fault – Onboard CSU time-out. Check PCB for damage.

E.02 – .17

Permanent Fault – Permanent loss of communication between the gas valve and boiler PCB. Fault in air/gas unit. Loose connection to the gas valve.

E.02 – .19

Permanent Fault – Jumper 1 changed. Check the position of jumper 1.

E.02 – .20

Permanent Fault – Jumper 2 changed. Check the position of jumper 2.

E.02 – .21

Permanent Fault – Jumper 3 changed. Check the position of jumper 3.

E.02 – .47

Permanent Fault – Connection to external device unsuccessful. Check wiring to external device.

E.02 – .48

Permanent Fault – Configuration to external device unsuccessful. Check pairing to external.

E.04 – .00

Permanent Fault – Gas valve fault. Gas valve not detected.

E.04 – .01

Permanent Fault – Flow temperature sensor short-circuited. Sensor not or badly connected. Bad connection. Sensor fault.

E.04 – .02

Permanent Fault – Flow temperature sensor open-circuited. Sensor not or badly connected. Bad connection. 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. Sensor fault.

E.04 – .05

Permanent Fault – Flue temperature sensor open-circuited. Sensor not or badly connected. Bad connection. Sensor fault.

E.04 – .06

Permanent Fault – Critical flue gas temperature value reached. No circulation. 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. 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 presents even though there is no flame. The burner remains very hot (CO2 is too high). Defective gas/air unit.

E.04 – .13

Permanent Fault – Fan rotor blocked. Fan seized. Wiring to fan damaged.

E.04 – .17

Permanent Fault – Problem with the gas valve. Defective gas/air unit.