High
E.01 – .12 on Baxi 400 Combi (range)

Your boiler has sensed that the water returning from your radiators is hotter than the water leaving the boiler, which usually means the water isn't circulating correctly or a sensor has developed a fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

Requires reset – temperature measured by return sensor greater than flow temperature.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

E110View →E125View →

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