How much does it cost to fix Worcester Bosch error code A0?

Typical repair cost for the Worcester Bosch A0 fault is £150-250 including labour.

A0 High

Worcester Bosch A0 Fault Code

Q: What does the Worcester Bosch A0 fault code mean?

Your boiler is struggling to accurately measure the temperature of the water inside its internal storage tank, which means your hot water may not heat up correctly.

The Worcester Bosch A0 fault code means: your boiler is struggling to accurately measure the temperature of the water inside its internal storage tank, which means your hot water may not heat up correctly.. It appears on 1 Worcester Bosch model in our database.

Technical description: Thermal store sensor defective

Typical repair cost £150-250 (including labour)

Engineer required

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

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Worcester Bosch models that show the A0 fault code

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

Greenstar Heatslave II Repair: £150-250

Source

Worcester Bosch A0 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.

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