Emergency
0A on Viessmann Vitodens 111-W B1LD 26kW

Your boiler has shut itself off because its flame is producing too much carbon monoxide, which means the burner is probably blocked and needs a Gas Safe engineer to check it before the boiler is 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 blocked. CO limiter (if installed) has responded. CO concentration too high.

From this model's manual
Verified against the Viessmann/Viessmann Vitodens 111 W B1ld 5697789 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

0DView →0FView →

All 28 fault codes on the Vitodens 111-W B1LD 26kW

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

0C1018303850515859A3A9b0b7b8E3E5F0F1F2F3F4F8F9FAFCFdFF

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