High
Fn on Ideal Atlantic Combi

Your boiler has unsuccessfully tried to start its internal flame and has switched itself off 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 Loss

From this model's manual
Verified against the Ideal/Ideal Atlantic Combi installation & service manual, page 55.
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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All 59 fault codes on the Atlantic Combi

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

4.34.44.54.64.74.84.94.104.114.1282838485868990F[-]F1F2F2 or Fn or LnF3F4F5F6F7F8F8 or L8F8/L8F9F9 or L9F9/L9FAFan faultFlame lossFlow thermistor faultFUIgnition lockoutL 2L CL[-]L1L4L4 or F4L5L5 or F5L6L8L9LnLow mains voltageLow water pressureNo DisplayOutside sensor faultOverheat lockoutPCB FaultReturn thermistor faultWater Pressure

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