Medium
353 on Viessmann Vitodens 100-W B1GA

Your boiler is not receiving enough gas to run at full power, so it has automatically lowered its performance to stay operational.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

Insufficient gas supply; burner output reduced

Shared across the Vitodens 100-W Heat Only range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Check that your gas meter has credit (if using a pre-payment meter).Ensure your external gas emergency control valve is fully open.Check if other gas appliances, like a hob, are working correctly to rule out a wider supply issue.

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Related fault codes

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All 105 fault codes on the Vitodens 100-W B1GA

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

78131449505758596263676869707173747789919295100103104142160161163182183184185345346348349350351352354355357359361365366367369370372373377378379380381382385386387388395396399400401402403404405406408410416417418425446447448449450451452453454455456457463464467468471474517527528540544545738

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