E18 High

ECA E18 Fault Code

The ECA E18 fault code means: your boiler has detected an unusually rapid rise in temperature and has shut down as a safety precaution to prevent overheating.. It appears on 3 ECA models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Temperature Sensor Error (lockout) — temperature change on sensor is too high (>30°C); press Reset; if persists notify ECA authorised service
Typical repair cost £120-250 (including labour)

DIY fix possible

Press the Reset button on the control panel onceCheck that all radiator valves are fully open to allow water to circulateEnsure your system pressure is topped up to between 1.0 and 1.5 bar

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ECA models that show the E18 fault code

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

Source

ECA E18 fault code information on this page is sourced and cross-checked against the official ECA service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026