What does the Worcester Bosch A1 fault code mean?

Your boiler has detected that the water inside the system is too low or has trapped air, preventing the water pump from working correctly.

How much does it cost to fix Worcester Bosch error code A1?

Typical repair cost for the Worcester Bosch A1 fault is £90-180 including labour.

Check your boiler's pressure gauge; if it is below 1 bar, increase the pressure to 1.5 bar using the filling loop.

Pump is running dry - check system pressure and bleed radiators

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Six most common causes of dropping pressure.

Step-by-step using the filling loop.

Each noise points to a different fault.