BoilerFaultCodesKeston E19 Fault Code
The Keston E19 fault code means: your boiler has switched itself off because the water returning to it is too hot, which usually means the water isn't moving through your radiators properly.. It appears on 1 Keston model in our database.
Technical description: Maximum return temperature exceeded – check circulation
DIY fix possible
Ensure all radiator valves (TRVs) are fully open to allow water to flow.Check that your external heating pump (if visible) is running and making a humming sound.Check that your central heating bypass valve is not closed too tightly.
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Keston models that show the E19 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Keston E19 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 7 July 2026