Unknown
e03 on Main Eco 24 HE

Main Eco 24 HE fault code e03

What the manual says

Manufacturer manual

Flow temperature sensor open circuit

From this model's manual
Verified against the Main/Main Maineco Combi 24 installation & service manual.
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 fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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All 50 fault codes on the Eco 24 HE

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