Explosive ignition Emergency

Worcester Bosch Explosive ignition Fault Code

Also written as EXPLOSIVEIGNITION — same fault.

The Worcester Bosch Explosive ignition fault code means: your boiler is struggling to light smoothly, causing it to build up a small amount of gas before igniting with a loud bang.. It appears on 1 Worcester Bosch model in our database.

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

Technical description: Reduced pilot flame or Faulty slow ignition valve
Typical repair cost £150-300 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Worcester Bosch models that show the Explosive ignition fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Worcester Bosch Explosive ignition 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