High
F.29 on Vaillant ecoTEC plus 937

Your boiler tried to stay lit, but the flame went out and it couldn't restart because the gas supply was interrupted or it couldn't detect the flame properly.

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

Flame goes off during operation and subsequent ignition attempts failed - Gas supply temporarily interrupted, defective earthing of the unit

From this model's manual
Verified against the Vaillant/Vaillant Ecotec Plus 937 Vui Gb 376 3 5 Isim 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

F.28View →F.27View →F.54View →

All 38 fault codes on the ecoTEC plus 937

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

conF.0F.01F.02F.03F.10F.11F.12F.13F.20F.22F.23F.24F.25F.27F.28F.32F.49F.61F.62F.63F.64F.65F.67F.70F.71F.72F.73F.74F.75F.76F.77F.78F.80F.81F.90F.91

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