How do I fix Worcester Bosch A5?

Try first: Try resetting the boiler once (your manual shows how); If the code comes straight back, it needs a Gas Safe engineer — don't open the boiler yourself. If that doesn't clear it, the likely part is Fan or air-pressure switch.

Worcester Bosch A5 Fault — What It Means & Fix Cost

⚠ 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:

Try resetting the boiler once (your manual shows how)
If the code comes straight back, it needs a Gas Safe engineer — don't open the boiler yourself

🔧 If that doesn't fix it

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

Most likely part: Fan or air-pressure switch

Fixed repair price

£576

Inc. VAT — part & labour, no surprise callout fee. You only pay if you go ahead.

A vetted Gas Safe engineer who covers your postcode will call you back to arrange the repair. No callout fee — you only pay if you go ahead.

Other Worcester Bosch fault codes

Worcester Bosch A1Pump stuck or running dry.…Worcester Bosch A61Gas valve fault.…Worcester Bosch C6Fan speed error — the fan isn't running at the expected spee…Worcester Bosch CE201Flow temperature sensor fault.…

Worcester Bosch A5 — what it means

✅ Try these first — they're free

🔧 If that doesn't fix it

Other Worcester Bosch fault codes

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