BoilerFaultCodesKeston E08 Fault Code
The Keston E08 fault code means: your boiler is having trouble managing the flame and electrical signals, which is preventing it from heating your home safely.. It appears on 9 Keston models in our database.
Technical description: Flame circuit error - possible control box fault..
What causes the Keston E08 fault?
This fault occurs when the boiler's internal computer is unable to correctly process the electrical signals required to monitor the flame. It is usually caused by a communication failure between the sensing hardware and the main control board, meaning the boiler shuts down because it cannot verify that it is burning gas safely. In many cases, this is due to moisture on the electronics or a component failure within the circuit board itself.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Keston models that show the E08 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Keston E08 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