High
F9 on Viessmann Vitodens 100-W B1HC-19

Your boiler has stopped working because the internal fan is failing to spin fast enough when trying to start up.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Burner in a fault state, Fan speed too low during burner start, Check the fan, fan connecting cables, fan power supply and fan control. Press "Reset" (see page 50).

From this model's manual
Verified against the Viessmann/Viessmann Vitodens 100 W B1hc B1kc 19 35 installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

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All 29 fault codes on the Vitodens 100-W B1HC-19

Seeing a different code? Every code this model can display, in one place.

0C5A101830385051525859A3A9b0b7b8E3E5F0F1F2F3F4F8FAFCFdFF

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