BoilerFaultCodesWhat the manual says
Manufacturer manualDisplay shows F9 on power on (Unprogrammed PCB)
From this model's manual
Verified against the Ideal Logic Combi Esp1 installation & service manual.
What causes this fault?
This fault occurs when the boiler's internal computer brain is blank and hasn't been told which specific model it is installed in. This usually happens because a new part was recently fitted but not configured, or because a sudden electrical glitch has caused the memory to wipe itself.
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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