Low Warning
59:0 on Viessmann Vitodens 300-W

Your boiler is notifying you of a minor adjustment in how it monitors your hot water tank temperature, which shouldn't immediately stop your system from working.

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

DHW cylinder loading: Starting point -2.5K Stopping point +2.5K

What causes this fault?

This fault occurs when the boiler receives inconsistent or missing data from the probe that monitors your hot water tank. The most common reason is a failing temperature sensor or a loose wire connection, which prevents the boiler from knowing exactly how hot your water is. Without this accurate information, the system cannot safely regulate the heating of your cylinder.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

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