Low
S.16 on Vaillant ecoTEC plus aquaPLUS

Your boiler's fan is staying on for longer than usual after you have used hot water to help cool the internal components down.

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.

What the manual says

Manufacturer manual

Fan over run (hot water operation)

From this model's manual
Verified against the Vaillant Ecotec Plus Aquaplus installation & service manual, page 38.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Check if your hot water taps are fully closedMonitor the display to see if the code clears automatically after a few minutesEnsure the boiler's casing ventilation is not obstructed

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