Low Warning
7b:1 on Viessmann Vitodens 300-W

Your boiler is having a minor communication issue where it cannot sync its internal clock with other connected heating 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

Send time to LON

What causes this fault?

This fault occurs when the boiler's internal control board fails to transmit the current time and date across the communication network to other system components. It is almost always caused by a software configuration error or a conflict in the settings between the boiler and an external control module. Because it is a data sync issue rather than a mechanical failure, it rarely requires physical parts to be replaced.

DIY fix possible

Locate the main control panel and access the Menu.Go to Settings and find the Date/Time option.Manually reset the time and date to ensure the system updates its internal clock.

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Related fault codes

7b:0View →

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