Low
S.15 on Vaillant ecoTEC exclusive 838

Your boiler is currently running a standard self-check or moving water through the system, which is a normal part of its operation.

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 and pump running

From this model's manual
Verified against the Vaillant/Vaillant Ecotec Exclusive 74c27d installation & service manual, page 43.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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.13View →S.14View →S.16View →

All 71 fault codes on the ecoTEC exclusive 838

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

conF.0F.1F.10F.11F.13F.20F.22F.23F.24F.25F.27F.28F.29F.32F.49F.61F.62F.63F.64F.65F.67F.70F.71F.72F.73F.74F.75F.76F.77P.0P.1P.2P.5P.6S.0S.1S.2S.3S.4S.5S.6S.7S.8S.10S.11S.13S.14S.16S.17S.20S.21S.23S.24S.25S.26S.27S.28S.30S.31S.32S.34S.36S.41S.42S.53S.54S.96S.97S.98

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