Low Information
73:0 on Viessmann Vitodens 333-F

Your boiler's hot water circulation pump is currently active based on its programmed timer settings.

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 is a status message rather than a mechanical failure, occurring when the boiler's internal clock triggers the secondary hot water pump to run. It indicates that the system is successfully moving hot water around your pipes so it is instantly available at your taps. You may see this code during your scheduled 'on' periods or if the pump has been manually boosted.

DIY fix possible

Check the hot water time program settings on your control panelAdjust the 'Circulation Pump' schedule if the pump is running when you do not need itMonitor the boiler to ensure it returns to standby once the scheduled period ends

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