E03 High

ECA E03 Fault Code

The ECA E03 fault code means: your boiler has temporarily shut down because the water inside it has become too hot, triggering a vital safety cutoff to prevent overheating.. It appears on 4 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: High Limit Temperature Protection
Typical repair cost £100-250 (including labour)

Engineer required

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

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ECA models that show the E03 fault code

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

Source

ECA E03 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