126 Medium

ECA 126 Fault Code

The ECA 126 fault code means: your boiler is struggling to get your hot water up to the right temperature, meaning your taps or shower may only be lukewarm.. It appears on 1 ECA model 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: DHW feeding temperature not reached
Typical repair cost £100-250 (including labour)

DIY fix possible

Check that the hot water temperature dial on the boiler is not set too lowEnsure the water flow rate at the tap isn't too high for the boiler to keep up withCheck if any other hot taps are running at the same time and turn them off

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ECA models that show the 126 fault code

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

Source

ECA 126 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