BoilerFaultCodesKeston E30 Fault Code
The Keston E30 fault code means: your boiler has detected an electrical fault with the internal sensor that monitors water temperature, causing the system to stop working for safety.. It appears on 9 Keston models in our database.
Technical description: Flow sensor short circuit – check connections to flow sensor
What causes the Keston E30 fault?
This fault occurs when the boiler's internal computer receives an incorrect electrical signal from the sensor that monitors hot water leaving the unit. The most common reason is that the sensor has suffered an internal electrical failure or the delicate wiring connecting it to the main control board has become damaged or loose.
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 E30 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Keston E30 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