Medium
12 on Alpha Intec 40GS2

Your boiler is struggling to detect the temperature of your hot water cylinder, which means it may fail to heat your taps or shower correctly.

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

Cylinder sensor fault (InTec S and FlowSmart only) - Incorrect cylinder sensor resistance

From this model's manual
Verified against the Alpha/Alpha Intec 40gs2 installation & service manual, page 41.
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

20View →

All 36 fault codes on the Intec 40GS2

Seeing a different code? Every code this model can display, in one place.

0102030405060810151620242527293137384344464751d0d1d2d3d4d5d6d7d8d9E03E38

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