109 High

ECA 109 Fault Code

The ECA 109 fault code means: your boiler has detected that the water inside is getting too hot, causing it to shut down for safety.. It appears on 1 ECA model 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: Boiler temperature control
Typical repair cost £100-280 (including labour)

DIY fix possible

Check that all radiator valves are fully openEnsure the boiler pressure is between 1.0 and 1.5 barGently bleed any air from your radiatorsReset the boiler to see if the fault clears

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ECA models that show the 109 fault code

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

Source

ECA 109 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 7 July 2026