High
E41 on Ravenheat TS 100

Your boiler has detected that the water leaving the unit is a significantly different temperature than the water returning to it, which usually means the water isn't circulating properly.

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

Different flow/return temperatures

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

E05View →

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