What does the Atag Block 81 fault code mean?

Your boiler has stopped working because it can no longer detect a vital safety sensor that monitors exhaust gases.

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

Typical repair cost for the Atag Block 81 fault is £100-£220 including labour.

The flue gas sensor is not connected although it was 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.