Low Information
S.5 on Vaillant ecoTEC exclusive

Your boiler is pausing briefly because it has finished its heating cycle or has reached the required temperature and is now cooling down internal components.

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

Fan and water pump return water

What causes this fault?

This status occurs when the boiler has successfully met the heating demand and is simply finishing its operation. The internal fan and pump continue to run for a short period to move residual heat away from the heat exchanger and prevent the system from overheating. It is a normal part of the boiler's cooling process rather than an actual breakdown.

DIY fix possible

Wait for 5-10 minutes as this is often a normal part of the boiler's operationCheck that your room thermostat is not set lower than the current room temperatureEnsure all radiator valves are open to allow heat to dissipate

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Related fault codes

S.0View →S.7View →S.8View →

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