Low
D.91 on Vaillant Atmomax

Your boiler is checking for an external radio signal to automatically set the time and date using its outside sensor.

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

DCF status with connected external probe

DIY fix possible

This fault may be fixable without an engineer. Check your manual first.

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D.90View →

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