BoilerFaultCodesWhat the manual says
Manufacturer manualHeating mode – ignition sequence error
From this model's manual
Verified against the Vaillant/Vaillant Ecotec Pro Ecotec Plus Regular installation & service manual.
What causes this fault?
This fault occurs when the boiler attempts to start the combustion process but fails to detect a stable flame after several attempts. It is usually caused by a worn-out ignition spark plug that can no longer bridge the gap, or a failing gas valve that isn't providing the correct amount of fuel into the burner.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Related fault codes
All 101 fault codes on the ecoTEC Pro / ecoTEC Plus
Seeing a different code? Every code this model can display, in one place.
F.00F.01F.02F.03F.10F.11F.12F.13F.20F.22F.23F.24F.25F.26F.27F.28F.29F.32F.42F.49F.52F.53F.54F.55F.56F.57F.61F.62F.63F.64F.65F.67F.68F.70F.71F.72F.73F.74F.75F.77F.78F.80F.81F.82F.83F.84F.85F.90F.91F.92F.93F.94S.00S.01S.02S.04S.05S.06S.07S.08S.10S.11S.13S.14S.15S.16S.17S.20S.21S.22S.23S.24S.25S.26S.27S.28S.30S.31S.32S.34S.39S.40S.41S.42S.46S.53S.54S.57S.58S.61S.62S.63S.76S.88S.92S.93S.96S.97S.98S.99