0-A2 Low

Worcester Bosch 0-A2 Fault Code

Also written as 0A2 — same fault.

The Worcester Bosch 0-A2 fault code means: your boiler is operating in a service mode used for manual testing and checking heating temperatures.. It appears on 1 Worcester Bosch model in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Set temperature in manual operation: 30...60...82°C.
Typical repair cost £0-80 (including labour)

DIY fix possible

Check if the service button or chimney sweep mode has been accidentally activated.Turn the boiler off and back on at the main power switch to reset the control panel.Adjust the temperature dial or digital controls to exit the manual override menu.

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Worcester Bosch models that show the 0-A2 fault code

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

Source

Worcester Bosch 0-A2 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