What does the Atag Block 81 fault code mean?

Your boiler has stopped working because it cannot detect a safety component that monitors exhaust fumes, which prevents it from firing up.

How much does it cost to fix Atag error code Block 81?

Typical repair cost for the Atag Block 81 fault is £120-250 including labour.

The flue gas sensor is not connected although it has been connected to the control. The burner is blocked until the flue gas sensor is reconnected.

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

Safety-critical — turn off, read this.

7 signs repair isn't worth it anymore.

Break-even maths on monthly cover.