BoilerFaultCodesWorcester Bosch P1, P2, P3, P1... Fault Code
Also written as P1P2P3P1 — same fault.
The Worcester Bosch P1, P2, P3, P1... fault code means: your boiler is simply going through its normal startup and self-test sequence after being turned on or reset.. It appears on 17 Worcester Bosch models in our database.
Technical description: Please wait, initialisation in progress.
What causes the Worcester Bosch P1, P2, P3, P1... fault?
This sequence occurs when the boiler's internal computer begins its startup and safety checks after the power has been switched on or the reset button pressed. It is not a fault, but rather the boiler confirming all internal components are communicating correctly before it begins the ignition process. Think of it like a computer booting up its operating system before it is ready for use.
DIY fix possible
Wait for approximately 30 to 60 seconds for the sequence to finishEnsure the boiler power is left switched onIf the code persists for more than 5 minutes, try a single reset
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Gas Safe Register →Worcester Bosch models that show the P1, P2, P3, P1... fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch P1, P2, P3, P1... 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