Baxi Boiler Fault & Error Codes

Baxi boilers are typically seen as reliable boilers, however even the most reliable boilers can go wrong from time to time. If your boiler has developed a fault then it will usually display a fault or error code of some kind.

Determining what the error code means is another story, but we've made it as easy as possible to find your error code and the potential cause. If you are unable to fix the issue then don't hesitate to fill out our contact form at the top of the page, if you do so one of our trusted boiler engineer partners will get in touch and help you diagnose and hopefully fix the problem.

Baxi "E" Fault Codes

This section is an overview of all the "E" labelled fault codes that could appear on your Baxi boiler.

Fault CodePotential Cause
E10Sensor error on the outside
E20Sensor fault on the central heating thermostat
E28Fault with the flue thermistor
E54Sensor fault on HW Flow
E78Sensor fault for water pressure
E100PCB internal clock time error
E109Circulation is poor

Numerical Fault Codes

Here is a list of all of the numerical fault codes that can appear on your Baxi boiler.

Fault CodesPotential Cause
110Overheating
111Flow temperature at a maximum limit
117The water pressure is too high
118The water pressure is too low
119Below <0.5 bar of pressure, system pressure is low
125Fault for the water circulation
127Legionella protection temperature not reached
128During operation there has been a loss of flame
133The safety time to establish a flame has been exceeded
153Force reset unit unlocked
160Faulty fan
162Switch error due to air pressure
164UK: Pressure sensor error

Ireland: heating flow switch error
166Switch fault due to air pressure
270Dry fire
432Earth connector error
433The heat exchanger temperature has been exceeded

Fault Code Terminology & Abbreviations

If there are some terms or abbreviations in the fault code table that you are unsure of the meaning of you can find a description below:

AbbreviationMeaning
DHWDomestic hot water
HRUHeat recovery unit
LTHLow temperature heating
PCUPrimary control unit - Electronic system to control burner function
SCUSecondary control unit - Additional electronic system