Fan is noisy even on the lowest speed.
The pre-filter is clogged with dust.
Clean the pre-filter properly.
The filter is clogged with dust.
Replace the whole filter.
The appliance makes a sudden loud noise while operating.
The operating mode is set to Smart mode or the fan speed is on Auto.
It may make a sudden noise as it automatically adjusts the air flow depending on indoor air quality.
A noise is generated when I start or stop the clean booster.
The clean booster is looking for the correct location.
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