Your boiler is currently performing a routine self-cleaning cycle to clear any fumes from the system before it attempts to ignite.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: Purgingthecombustionchamber,faninoperation
What causes this fault?
This status occurs when the boiler detects a need to clear the internal combustion area of any residual gases or debris before it can safely start the burner. It is a natural part of the boiler's safety protocol, triggered by the fan spinning at high speed to ensure a clean environment for ignition. This cycle is usually temporary and does not signify that a component has failed.
DIY fix possible
Wait for the process to complete, as this is a normal status message and not a breakdownEnsure there are no obstructions around the external flue pipe outside your homeIf the code persists for several minutes without the boiler firing up, try resetting the boiler once
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