How much does it cost to fix Atag error code b28?

Typical repair cost for the Atag b28 fault is £180-450 including labour.

b28 High

Atag b28 Fault Code

Q: What does the Atag b28 fault code mean?

Your boiler has switched itself off because the internal fan, which safely clears exhaust gases, is not spinning at the correct speed.

Also written as B28 — same fault.

The Atag b28 fault code means: your boiler has switched itself off because the internal fan, which safely clears exhaust gases, is not spinning at the correct speed.. It appears on 1 Atag model in our database.

Technical description: Boiler block: Fan speed error

Typical repair cost £180-450 (including labour)

Engineer required

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

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Atag models that show the b28 fault code

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

E Range Repair: £180-450

Source

Atag b28 fault code information on this page is sourced and cross-checked against the official Atag service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026