How much does it cost to fix Keston error code E 25?

Typical repair cost for the Keston E 25 fault is £120-250 including labour.

E 25 High

Keston E 25 Fault Code

Q: What does the Keston E 25 fault code mean?

Your boiler is struggling to pump water around your heating system quickly enough, causing the water inside to get hot too fast and triggering a safety shutdown.

Also written as E25 — same fault.

The Keston E 25 fault code means: your boiler is struggling to pump water around your heating system quickly enough, causing the water inside to get hot too fast and triggering a safety shutdown.. It appears on 3 Keston models in our database.

Technical description: Flow temperature increased too quickly. Check water circulation.

Typical repair cost £120-250 (including labour)

DIY fix possible

Check that all radiator valves throughout your home are fully open.Inspect the boiler pressure gauge to ensure it is within the normal green operating range (usually 1.0 to 1.5 bar).Turn the boiler off at the fused spur and back on again after 30 seconds to attempt a system reset.

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Keston models that show the E 25 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Keston E 25 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