0F
FAULT CODE
Viessmann
Boiler Service Required
Low Severity
DIY Check Possible
Not a fault — this is a maintenance reminder indicating the boiler is due for its annual service.
Step-by-Step Fix Guide
-
Step 1
Book an annual service with a Gas Safe registered engineer
-
Step 2
After servicing, the engineer will reset the service indicator
Gas Safe Reminder
Work on gas appliances must be carried out by a Gas Safe registered engineer. The steps above cover safe checks a homeowner can perform - any internal component replacement requires a qualified professional. If in doubt, always call an engineer.