Low Information
72:0 on Viessmann Vitodens 300-W

Your boiler is notifying you that your hot water circulation pump is currently running as scheduled, but it may be staying active because of a sensor communication issue.

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 circulation pump: ON according to time program

What causes this fault?

This code appears when the boiler’s internal control unit recognizes that the secondary hot water pump is running as per its scheduled timer. It is typically a status notification rather than a breakdown, though it can sometimes be triggered by a slight delay in the electrical signal between the pump and the main circuit board. You will usually find your hot water is working perfectly while this code is displayed.

DIY fix possible

Check your hot water time program settings on the control panelSwitch the boiler off and back on to refresh the system communicationMonitor for any changes in hot water temperature or delivery speed

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F4View →72:1View →

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