Before any maintenances are done, make sure that the control unit is turned off. Services shall not be done while using the product. 

To replace the air filter: 

1. Loosen the small protective plate on the rear of the control unit using a size T10 Torx screwdriver.
2. Remove the filter from the holder. 
3. Place the new filter in the holder with the pink side facing outwards. Put the protective plate back in place and secure using the screws. 

If the control unit is used in a very dirty environment the filter should be checked regularly.

For more information and to learn more about the CuroCell A4 product line, along with other Care of Sweden products, visit the Crescent Healthcare website, and check out the articles under the Care of Sweden category.