Manufacturer directory

Viessmann Boiler Fault Codes

Fault-code information for Viessmann boilers, grouped by verified boiler range. Each entry is linked to its own fault-code page.

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Popular boiler ranges

Verified fault-code index

Viessmann fault-code checker — all-boiler row

F6 — Viessmann fault-code checker — all-boiler row
Fan not at standstill / plug-in connection.
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Vitodens 200 fault-code checker row

OC — Vitodens 200 fault-code checker row
Flame signal still present after switching off.
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Vitodens 222F fault-code checker row

A4 — Vitodens 222F fault-code checker row
Air lock in the internal circulation pump or minimum flow rate not achieved.
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Vitodens fault-code checker row

OC — Vitodens fault-code checker row
Insufficient power supply.
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Vitodens/Vitotronic fault-code checker row for outdoor sensor