How much does it cost to fix Worcester Bosch error code Fault 55 / 146?

Typical repair cost for the Worcester Bosch Fault 55 / 146 fault is £80-120 including labour.

Fault 55 / 146 Low

Worcester Bosch Fault 55 / 146 Fault Code

Q: What does the Worcester Bosch Fault 55 / 146 fault code mean?

Your boiler is displaying an advisory message stating that its built-in solar heating controls have not been set up or activated.

Also written as FAULT55146 — same fault.

The Worcester Bosch Fault 55 / 146 fault code means: your boiler is displaying an advisory message stating that its built-in solar heating controls have not been set up or activated.. It appears on 2 Worcester Bosch models in our database.

Technical description: Solar system not yet commissioned: Solar system is not yet in operation.

What causes the Worcester Bosch Fault 55 / 146 fault?

This code appears because the boiler’s internal computer is searching for a solar thermal heating system that hasn't been programmed yet. It usually happens if the control board was recently replaced or reset and the installer didn't tell the software whether solar panels are connected. While it looks like a fault, it is actually just a configuration setting that needs to be updated in the digital menu.

Typical repair cost £80-120 (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 Fault 55 / 146 fault code

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

Source

Worcester Bosch Fault 55 / 146 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