BoilerFaultCodesWorcester Bosch EA229 Fault Code
The Worcester Bosch EA229 fault code means: your boiler has lost its flame suddenly while it was running, causing it to stop heating your home for safety.. It appears on 2 Worcester Bosch models in our database.
Technical description: Loss of ionisation signal during operation
What causes the Worcester Bosch EA229 fault?
This fault occurs when the boiler’s control system suddenly loses the signal that confirms a flame is present while it is firing. The most common reason is that the flame is physically blowing out due to a gas supply issue, or the internal sensing probe has become too dirty or worn to detect the heat properly. It can also be caused by the boiler 'choking' on its own exhaust gases if there is a problem with the flue or air supply.
This fault is more common in winter, as frozen condensate pipes can cause backup issues that lead to a sudden loss of flame.
DIY fix possible
Check if other gas appliances like a hob are working to ensure you have a gas supplyCheck that your condensate pipe (outside) is not frozen during cold weatherPress the Reset button for five seconds and see if the boiler restarts
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Gas Safe Register →Worcester Bosch models that show the EA229 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch EA229 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026