Low
S.25 on Vaillant Home System

Your boiler is briefly keeping the pump running to cool down internal components after providing hot water.

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

DHW mode: Pump/fan overrun

From this model's manual
Verified against the Vaillant/Vaillant Home System installation & service manual, page 33.
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 hot water is still being produced normallyWait a few minutes for the status code to clear automaticallyNo action is required as this is a normal operating sequence

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Related fault codes

S.05View →S.24View →S.20View →

All 141 fault codes on the Home System

Seeing a different code? Every code this model can display, in one place.

cond.00d.01d.02d.04d.05d.06d.07d.08d.09d.10d.11d.13d.14d.15d.16d.17d.18d.19d.20d.21d.22d.23d.24d.25d.27d.28d.31d.33d.34d.35d.36d.39d.40d.41d.43d.45d.47d.50d.51d.58d.60d.61d.62d.64d.65d.66d.67d.68d.69d.70F.00F.01F.10F.11F.13F.20F.22F.23F.24F.25F.27F.28F.29F.32F.33F.49F.61F.62F.63F.64F.65F.67F.68F.70F.71F.72F.73F.74F.75F.77F.78F.83F.84F.85F.86F.87F.88F.89F22P.01P.02P.03P.04P.05P.06P.07S.0S.01S.02S.03S.04S.05S.06S.07S.08S.10S.11S.13S.14S.15S.16S.17S.20S.21S.22S.23S.24S.26S.27S.28S.30S.31S.32S.33S.34S.39S.41S.42S.46S.53S.54S.88S.91S.96S.97S.98S.99S.108S.109

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