BoilerFaultCodesKeston E01 Fault Code
The Keston E01 fault code means: your boiler has tried to light several times but cannot establish a steady flame, usually because there is no gas reaching the burner or the ignition sequence is blocked.. It appears on 9 Keston models in our database.
Technical description: Ignition failure – the boiler has attempted to light 5 times and not succeeded – check the gas supply is on
DIY fix possible
Check if other gas appliances in your home, like a hob, are working to confirm your gas supply is active.Ensure your gas meter has credit if you are on a prepaid meter.Check that the white condensate pipe leaving the boiler isn't frozen if it is cold outside.Reset the boiler by following the instructions on the display panel.
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Gas Safe Register →Keston models that show the E01 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Keston E01 fault code information on this page is sourced and cross-checked against the official Keston service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026