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Worcester Bosch · Error C6

Worcester Bosch C6 — what it means

Fan fault — the fan isn't spinning at the speed the boiler expects, so it won't fire for safety.

⚠ This is the likely cause from the code — a Gas Safe registered engineer confirms it on site. If you can smell gas, stop and ring 0800 111 999.

✅ Try these first — they're free

Often clears it without a callout:

  • Press reset once and listen for the fan spinning up on start

🔧 If that doesn't fix it

The likely cause is one of these — the engineer confirms which:

  • Failed fan
  • Loose fan wiring or connector
  • Blocked flue

Most likely part: Fan assembly

⚠ Worth knowing

  • A failing fan can leave debris that stresses the air-pressure switch — the engineer will check it
Fixed repair price
£260
Part + labour, no surprise callout fee. You only pay if you go ahead.
Book a Gas Safe engineer
You pick from the 3 nearest vetted engineers. Your choice gets first refusal; if they don't take it within a few hours it moves to the next nearest automatically — and we keep you posted.

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