Err.L - Err.5 Medium

Atag Err.L - Err.5 Fault Code

Also written as ERRLERR5 — same fault.

The Atag Err.L - Err.5 fault code means: your boiler is displaying a list showing the history of recent technical faults rather than a single active problem, suggesting the system has recorded errors while trying to manage its own performance.. It appears on 4 Atag models in our database.

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description: Last saved error until 5 last predecessing errors
Typical repair cost £120-250 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Atag models that show the Err.L - Err.5 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Atag Err.L - Err.5 fault code information on this page is sourced and cross-checked against the official Atag service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026