Low
d.11 on Vaillant ecoTEC Plus 938

Your boiler is simply reporting that a secondary pump, responsible for circulating water through your heating system, is currently not running.

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

Status of the heating circuit's shunt pump: off/on

DIY fix possible

Check if the room thermostat or programmer is calling for heatMonitor the display to see if the status changes when heating is activeEnsure there are no other fault codes (starting with 'F') present

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Related fault codes

d.10View →F.22View →

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