How much does it cost to fix Atag error code C1 29?

Typical repair cost for the Atag C1 29 fault is £200-350 including labour.

C1 29 High

Atag C1 29 Fault Code

Q: What does the Atag C1 29 fault code mean?

Your boiler's air circulation system isn't starting, which prevents the unit from firing up safely to provide heat or hot water.

Also written as C129 — same fault.

The Atag C1 29 fault code means: your boiler's air circulation system isn't starting, which prevents the unit from firing up safely to provide heat or hot water.. It appears on 4 Atag models in our database.

Technical description: Fan error (fan does not start up)

Typical repair cost £200-350 (including labour)

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 →

Atag models that show the C1 29 fault code

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

A200 Repair: £200-350
Q 25CR Repair: £250-450
S 25CR Repair: £250-450
Sov. Repair: £250-450

Source

Atag C1 29 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