Emergency
463 on Viessmann Vitodens 050-W B0KA-30-M

The boiler has shut itself down for safety because it is drawing in some of its own exhaust fumes instead of fresh air, and it needs a Gas Safe engineer to check the flue and air supply before it can be used again.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

What the manual says

Manufacturer manual

Burner in a fault state. Contaminated combustion air, flue gas recirculation

From this model's manual
Verified against the Viessmann/Viessmann Vitodens 050 W B0ha B0ka 6194588 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 emergency 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

462View →464View →

All 131 fault codes on the Vitodens 050-W B0KA-30-M

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

78131449505758596263646768697071727374757778878995104142161163182183184299346347348349350351352353354355357359361364365366367369370371372373374375376377378379380381382383384385386387388393394399400401402403404405406408410416417418425446447448449450451452453454455456457458461462464467468471474527528540574575576577578579682683684694738766767799979980981982E10E12

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