E125 High

Baxi E125 Fault Code

The Baxi E125 fault code means: your boiler is struggling to move water around the system properly, which is causing it to shut down to prevent overheating.. It appears on 12 Baxi 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: Primary circuit error circulation fault

What causes the Baxi E125 fault?

This fault occurs when the boiler detects that water is not moving through the internal pipes quickly enough to take the heat away from the burner. The most common reasons are a failed pump that can no longer push the water, or a blockage caused by a build-up of sludge and debris in the system. Because the heat cannot escape, the boiler shuts down as a safety precaution to prevent the internal components from melting or cracking.

This fault often appears during the first cold snap of autumn when a heating system that has been sitting idle all summer is suddenly forced to move heavy, settled sludge.

Typical repair cost £180-450 (including labour)

DIY fix possible

Check that all radiator valves (TRVs) are fully openEnsure your system pressure is between 1.0 and 1.5 bar on the gaugeTry resetting the boiler to see if the error clears

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Baxi models that show the E125 fault code

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

Source

Baxi E125 fault code information on this page is sourced and cross-checked against the official Baxi service / installation manuals for each affected model.

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