How much does it cost to fix Atag error code 154?

Typical repair cost for the Atag 154 fault is £150-350 including labour.

154 High

Atag 154 Fault Code

Q: What does the Atag 154 fault code mean?

Your boiler has stopped working because it cannot move water through the system effectively, likely due to a circulation problem or a blockage.

The Atag 154 fault code means: your boiler has stopped working because it cannot move water through the system effectively, likely due to a circulation problem or a blockage.. It appears on 4 Atag models in our database.

Technical description: The control system will, if an unacceptable temperature difference is detected, repeatedly try to establish a water flow. If this does not succeed, the boiler will block itself (code 154).

Typical repair cost £150-350 (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 154 fault code

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

Source

Atag 154 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