Medium
S.17 on Vaillant Combi Compact 242EB

Your boiler has finished providing hot water, but the pump is struggling to circulate the remaining heat away from the system, likely due to a blockage or a valve issue.

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

DHW mode – pump overrun error

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

S.10View →S.11View →

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