Low
S.17 on Vaillant Thermocompact

Your boiler is currently running its pump to safely move heat away from the system after making hot water, which is a normal part of the cooling-down process.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

Pump over run (hot water operation)

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.16View →

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