BoilerFaultCodesViessmann 62:1 to 62:15 Fault Code
Also written as 621TO6215 — same fault.
The Viessmann 62:1 to 62:15 fault code means: your boiler is notifying you of the current pump run-on settings rather than an actual fault, essentially staying operational for a set time after central heating is turned off.. It appears on 5 Viessmann models in our database.
Technical description: Run-on time adjustable from 1 to 15 minutes
What causes the Viessmann 62:1 to 62:15 fault?
This is not a mechanical failure but rather a custom setting that dictates how long the internal pump continues to circulate water after the burners have turned off. It is designed to dissipate residual heat from the heat exchanger to protect the internal components from overheating. If you see this code, it simply means the boiler is carrying out its programmed cooling cycle before coming to a complete stop.
DIY fix possible
Check the user manual to see if you wish to adjust the fan or pump run-on duration.No action is required if the boiler is providing heating and hot water as normal.Restart the boiler to clear the display if it is stuck on this status code.
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Gas Safe Register →Viessmann models that show the 62:1 to 62:15 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Viessmann 62:1 to 62:15 fault code information on this page is sourced and cross-checked against the official Viessmann service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026