BoilerFaultCodesWorcester Bosch C2 Fault Code
The Worcester Bosch C2 fault code means: your boiler has detected a problem with the way gas is being supplied or ignited at the burner, preventing it from heating your water.. It appears on 2 Worcester Bosch models in our database.
Technical description: Burner injection
What causes the Worcester Bosch C2 fault?
This fault occurs when the boiler's control system detects that gas isn't reaching the burner correctly or isn't staying lit once ignited. The most common reasons are a malfunctioning gas valve that won't open properly or ignition electrodes that have become worn and can no longer create a reliable spark.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Worcester Bosch models that show the C2 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch C2 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