Do you have a "Bagless" Vacuum?
That means that you need to clean your filter and maintain other parts to keep it running well.
here's what I do regularly.
1. If the beater brush isn't spinning well, the belt may need to be replaced. Just locate the screws that hold the cover in place, open it up and find the rubber belt. My 10-year-old vacuum is still working hard with a new belt in place!
3. This is the MOST IMPORTANT!! After every 3 or 4 full dirt cups, I thorough clean the foam sponge and plastic dirt cups. Once the foam sponge gets clogged with dirt the vacuum won't really "suck." I rinse every piece in my sink and let them air dry before the next vacuuming.
One of my best yard sale finds is a small Bissell bagless vacuum I bought for $8. The seller insisted that, even though it was brand new, it didn't suck up any dirt. I plugged it in and heard that the motor was running strong and the brush was turning well. I bought it, took it home, and within minutes found a huge hair/dirt ball stuck in the hose. I cleaned the foam filter and dirt cup, and discovered that this beauty works just fine! 5 years later, it's going strong!