What does the Atag Err.4 fault code mean?

Your boiler has detected a series of internal faults that are preventing it from operating safely, causing it to lock itself out.

How much does it cost to fix Atag error code Err.4?

Typical repair cost for the Atag Err.4 fault is £150-300 including labour.

Predecessing error 4

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

Lockout fault with a reset-needed pattern.

Safety-critical — turn off, read this.

7 signs repair isn't worth it anymore.