Low
D.81 on Vaillant Atmomax

This is an information code rather than a fault, showing you the total number of hours the boiler has spent heating your 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

Operating hours hot water generation

Shared across the range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
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

No action is required as this is an advisory status messagePress the 'i' button to exit the information menuMonitor the boiler for any actual fault codes (starting with 'F')

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Related fault codes

D.80View →D.82View →D.83View →

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