BoilerFaultCodesKeston E24 Fault Code
The Keston E24 fault code means: your boiler has shut down because it keeps losing water pressure and likely has a leak somewhere in the heating system or the unit itself.. It appears on 9 Keston models in our database.
Technical description: Water pressure losses - You have topped up the water pressure more than 4 times in 24 hours. You may have a leak on the system..
What causes the Keston E24 fault?
This fault occurs because the boiler has detected a significant and repetitive drop in water pressure, forcing it to shut down to prevent internal damage. It is usually caused by a physical leak within your radiators, pipework, or the boiler's internal components, such as a failing pressure relief valve. If the system cannot maintain a steady pressure four times within a single day, the software triggers this safety lock to alert you to the underlying leak.
This fault is frequently seen in autumn when the heating is turned back on after summer, as the change in temperature and pressure can cause weakened seals or joints to start leaking.
DIY fix possible
Check for visible water leaks under the boiler and around your radiators or valves.Top up the system pressure to 1.5 bar using the external filling loop.Reset the boiler and monitor if the pressure drops again.
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Gas Safe Register →Keston models that show the E24 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Keston E24 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