Technical description
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What causes this fault?
This fault occurs when a newly installed circuit board has not been configured to recognize the specific power output of your boiler. Because the same spare part is used across multiple models, the boiler remains in a safety mode until it is told exactly which version it is operating. This usually happens immediately after a repair or if the internal memory has been corrupted by a power surge.
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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