Medium
D6 on Worcester Bosch Greenstar 25 HE Combi

Your boiler's internal water storage tank is overfilling, which could eventually lead to water leaking from the unit.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

Technical description

Internal heat bank overflow

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 →D5View →

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