Display shows F7 and regeneration does not start at the programmed time

Safety first: No hydraulic work is needed for this fault; keep covers closed.

• Check time settings: Enter the programming menu and verify the current time, date, and regeneration time. Correct any errors.
• Verify regeneration mode: Ensure the unit is set to meter-initiated or time-initiated regeneration as required, and that the capacity or interval is not set too high.
• Check for power loss: If the display resets after power cuts, the internal backup (battery or capacitor) may be failing. Note if the clock loses time frequently.
• Perform a factory reset: If allowed by the manual, perform a factory reset and reprogram all parameters. Observe whether F7 returns.
• Board replacement: If the clock cannot keep time or F7 persists, the Viessmann control board will likely need replacement by a technician.