High
E.01 .12 on Baxi Assure System

Your boiler has detected that the water flowing back into it is hotter than the water flowing out, which confuses the system and causes it to shut down for safety.

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.

What the manual says

Manufacturer manual

Temperature measured by return sensor greater than flow temperature SENSOR/CONNECTION PROBLEM Check that the sensors are positioned the correct way around Check that the flow sensor is in the correct position Check the return temperature in the boiler Check the operation of the sensors

From this model's manual
Verified against the Baxi Bm Baxi B Basic System 2 600 800 Assure 500 Isim installation & service manual, page 50.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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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