Hello! It sounds like your vacuum has lost suction. This is caused by either a clog or a filter that needs to be cleaned or replaced. Please try these brief trouble-shooting steps.
1. Remove the dirt cup. Twist off the dirt cup lid.
2. Remove the filter cartridge from dirt cup.
3. Separate the foam and cartridge filters. Wash foam filter under running. Allow 24 hours to air dry outside the vacuum.
4. Tap the excess dirt out of Hepa filter. Hepa filter may also be washed. Allow 24 hours to air dry.
5. Check the secondary filter by removing the filter cover from base. Rinse the foam filter under running water until it runs clear. Allow 24 hours to air dry.
6. The red baffle tube inside of the dirt cup is apart of the filtration of the vacuum and needs to be cleaned as well. Twist out the baffle tube by turning 1/4 turn clockwise. Remove any hair or debris wrapped around baffle tube. Baffle tube can be rinsed if needed. Allow to dry thoroughly.
7. Remove the hose from both ends. Use a broom stick to loosen and remove any clogs from the main hose.
8. Remove the bottom plate and the brushes as instructed in the owner's manual. Use a wooden spoon or something similar to gently break up and remove any clogs from the lower hose.
If the filters are too dirty they may need to be replaced. With regular maintenance the filters should be replaced about once a year. Follow the links below to order replacement filters for your UH20020.
Exhaust Foam Filter
Hope this was helpful!