High
F35 on Euroterm E27 Plus

Your boiler has detected an issue with the electricity supply entering your home, meaning the power quality is not stable enough for the boiler to operate safely.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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.

What the manual says

Manufacturer manual

Faulty mains frequency

Community-sourced, unverified
We could not tie this code to a specific manual. Treat it as indicative only.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

F34View →F36View →

All 38 fault codes on the E27 Plus

Seeing a different code? Every code this model can display, in one place.

A01A02A03A04A05A06A09A16A21A23A24A41A42A44A61A62A63A64A65F04F05F07F10F11F12F13F14F15F20F34F37F39F42F43F47F52F66

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