High
Flashing orange LED on Sime Murelle HE System

Your boiler is failing to recognise that the burner has lit, preventing it from heating your home for safety reasons.

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

Flame detection circuit fault — check ignition/detection electrode

Shared across the Murelle System HE range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
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

AL 02View →AL 06View →AL 07View →

All 25 fault codes on the Murelle HE System

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

ALARM 01ALARM 02ALARM 03ALARM 04ALARM 05ALARM 06ALARM 07ALL 02ALL 03ALL 04ALL 05ALL 06ALL 07ALL 08ALL 09ALL 10ALL 13ALL 14LED flashing after fanOrange LED flashingOrange LED onRed LED after flow switchRed LED on (after safety stat)Red LED on (solid)

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