Low
d.23 on Vaillant ecoFIT Pure 412

This code is simply a status message confirming that your boiler is currently waiting for a heating demand from your thermostat or timer.

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 demand (off=Heating off, on=Heating on)

DIY fix possible

Check your room thermostat is set to a higher temperature than the current room temperatureEnsure your programmer or digital timer is switched to the 'ON' positionVerify that any external smart home systems are not currently set to away or frost protection mode

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