BoilerFaultCodesWorcester Bosch P2 Fault Code
The Worcester Bosch P2 fault code means: your boiler's electronic control system has detected a failed safety fuse, meaning it cannot start up or provide heating and hot water until this internal electrical component is replaced.. It appears on 11 Worcester Bosch models in our database.
Technical description: Please wait, initialisation in progress. 24 V fuse blown.
What causes the Worcester Bosch P2 fault?
This code appears when the boiler is attempting to light the flame but the internal sensors haven't confirmed a successful ignition within the standard timeframe. It is often caused by a weak spark from a worn ignition electrode or a delay in the gas reaching the burner. While the boiler is trying to correct itself, it indicates that the ignition components are likely deteriorating or need cleaning.
This issue is more frequent during the first cold snap of autumn when a boiler that has been idle over summer is suddenly forced to work harder.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A cover plan would handle faults like P2: no call-out fees, no surprise bills.
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Worcester Bosch models that show the P2 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch P2 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.
- Worcester Bosch 537i manual (PDF)
- Worcester Bosch Greenstar 25 HE Combi manual (PDF)
- Worcester Bosch Greenstar 25HE manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026