How much does it cost to fix Atag error code E18?

Typical repair cost for the Atag E18 fault is £150-300 including labour.

E18 High

Atag E18 Fault Code

Q: What does the Atag E18 fault code mean?

Your boiler has shut down because the water inside is significantly hotter than it should be, which could indicate a circulation problem.

The Atag E18 fault code means: your boiler has shut down because the water inside is significantly hotter than it should be, which could indicate a circulation problem.. It appears on 1 Atag model in our database.

Technical description: High flow temperature (T1 > 95°C)

Typical repair cost £150-300 (including labour)

Engineer required

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

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

Gas Safe Register →

Atag models that show the E18 fault code

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

Premier Repair: £150-300

Source

Atag E18 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 27 April 2026