e10 High

Main e10 Fault Code

Also written as E10 — same fault.

The Main e10 fault code means: your boiler has temporarily stopped working because the water inside is not circulating properly between the heating pipes.. It appears on 2 Main models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Difference between the flow and return temperatures too great
Typical repair cost £100-£250 (including labour)

DIY fix possible

Check that your heating system pressure is at the correct level, usually between 1 and 1.5 bar on the pressure gauge.Ensure your radiators and thermostatic valves are open and not blocked, allowing water to flow freely.Try resetting the boiler using the reset button or turning the power off and on again.

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Main models that show the e10 fault code

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

Source

Main e10 fault code information on this page is sourced and cross-checked against the official Main service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026