Turn off the boiler and shut down the gas valve.
The most common fault codes for this model:
F.00 NTC Faults.
F.01 NTC Faults.
F.20 Overheat Problem.
F.22 Dry fire, low water in system/Overheat.
F.24 Low water, or Pump failure/blockage.
F.29 Flame extinguished. Fan/flue problem/Gas.
F.28 No ignition/Ignition problem. No gas!
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