Medium
d2 on Alpha Intec 40GS2

Your boiler is currently monitoring the temperature of the water as it leaves the unit to heat your home, but it is detecting an abnormal reading that is preventing it from firing up 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

Central heating water temperature leaving the boiler

From this model's manual
Verified against the Alpha Intec 40gs2 installation & service manual, page 28.
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

d1View →d3View →

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