Medium
d7 on Alpha Eco 11 13

Your boiler is struggling to read the temperature of the incoming water or the water stored in your hot water cylinder, which may result in inconsistent heating or hot water performance.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

Mains inlet temperature or FlowSmart cylinder temperature (if sensor fitted) °C

From this model's manual
Verified against the Alpha Eco installation & service manual, page 23.
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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Related fault codes

d6View →d8View →

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