What does the Biasi E11 fault code mean?

Your boiler thinks it sees a flame even though the gas should be turned off, which is a safety conflict causing the system to shut down.

How much does it cost to fix Biasi error code E11?

Typical repair cost for the Biasi E11 fault is £120-350 including labour.

Parasitic flame (flame detected with gas valve closed)

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

Older boilers — thermocouple, draught, gas supply.

Safety-critical — turn off, read this.

7 signs repair isn't worth it anymore.