Emergency
77 on Ideal Icos System

Your boiler is failing to detect the burner flame properly, so it has safely shut down to prevent any unburnt gas from building up.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

What the manual says

Manufacturer manual

FLAME DETECTION ERROR

From this model's manual
Verified against the Ideal/Ideal Icos System 4139152 installation & service 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 emergency 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

F4View →F9View →L9View →

All 11 fault codes on the Icos System

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

78H 1H 4H EH FH nL 8L AL EL F

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