What does the Biasi E21 fault code mean?

Your boiler has shut down because the waste water pipe that carries away condensation is blocked or frozen, causing water to back up into the unit.

How much does it cost to fix Biasi error code E21?

Typical repair cost for the Biasi E21 fault is £80-140 including labour.

Locate the plastic white pipe exiting the wall outside your property.

Condensate trap blockage or drain pipe obstruction

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

Winter cause of ignition lockouts.

Safety-critical — turn off, read this.

7 signs repair isn't worth it anymore.