What the manual says
Manufacturer manualFlame Loss
What causes this fault?
This fault occurs when the boiler's control board detects that the flame has gone out unexpectedly while the unit is firing. The most common reasons are a restricted gas supply, a build-up of carbon on the ignition sensors, or a faulty gas valve failing to maintain the correct flow of fuel.
This fault is more frequent during extreme cold spells, as frozen external gas meters or pipes can restrict the pressure needed to keep the flame stable.
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.
Avoid the next call-out bill
A cover plan would handle faults like Fn: no call-out fees, no surprise bills.
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