Miele S 8990 UniQ Operating manual - Page 24

Maintenance and care When to change the filter bag Change the filter bag when the colored marker in the airflow indicator completely fills the display in red. Filter bags are disposable articles and made to be used only once. Dispose of full filter bags. Do not attempt to reuse. Clogged pores reduce the suction power of the vacuum cleaner. Check the airflow indicator ^ Attach the standard floor brush (depending on model) to the vacuum cleaner. All other suction tools can affect the function of the airflow indicator. ^ Use the On/ Off foot switch s to switch the vacuum cleaner on, then select the highest suction setting. ^ Slightly lift the standard floor brush from the floor. If the color marker completely fills the indicator window, the filter bag needs to be changed. How the airflow indicator works The airflow indicator is designed to show when the bag is full of common household dust and measures the amount of air flow through the filter bag. Normal household dust is a mixture of dust, hair, carpet fluff, threads, sand, etc. However, if fine dust, such as drill dust, sand, plaster or flour is vacuumed, the pores of the filter bag may become blocked. The marker will indicate that the bag is "full" even when it is not. The filter bag should be changed as the suction power is greatly reduced. If the bag is bulging with pet fur, hair, carpet fluff, etc. the indicator may not register "full". This is because the air flow of the filter bag may still be high enough not to activate the marker to show maximum. The filter bag should still be changed. 24