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Cannot change date

Cannot Change Date - Date setting issue

Viessmann · Vitodens 200 Boilers

What does Cannot change date mean?

The user is unable to change the date setting on the boiler's control, which typically indicates a specific coding address needs adjustment.

Common Causes

  • Incorrect coding address for date settings

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Refer to coding address OC7 in the manual for instructions on changing the date.

  2. 2

    Adjust the OC7 coding as needed to set the correct date.

  3. 3

    Power cycle the boiler (power ON/OFF) for the date changes to take effect.

Browse all codes in this manual (21)
Verified technical data. Last updated: April 2026

Related Faults

06 / 07Fault 06 or 07 - Insufficient air supply or vent blockage14Fault 14 - Ignition failure or gas supply issue14 (multiple boilers)Fault 14 (Multiple Boilers) - One boiler locks out while others run
Source: Viessmann Vitodens 200 Boilers
Open Manual (Page 9)Search more codes in this manual