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Viessmann fault code

Viessmann FA: fan idle state not reached

Engineer only

Viessmann describes FA on Vitodens 100-W (B1HC/B1KC) boilers as: fan idle state not reached.

What you can safely do

There is nothing you can safely do yourself with this one. Leave the boiler off and book an engineer.

Find a Gas Safe engineer near you Opens the official Gas Safe Register search.

Applies to: Vitodens 100-W (B1HC/B1KC). Codes can differ between models, so check your manual.

From Viessmann's own fault tables. Your model name is usually on the front of the boiler or in the user manual.

Model	Meaning
Vitodens 100-W (B1HC/B1KC)	Fan idle state not reached

Can I fix Viessmann FA myself?

No. It needs a Gas Safe registered engineer to diagnose. Tell them the exact code and your boiler's model name.