FAQ Search Select a Category BarkBath Cleaning Formulas Cleaning Tips Commercial Products Corporate Deep Cleaners Hard Floor Cleaners Mops, Brooms and Brushes Parts and Accessories Steam Sweepers Vacuums Warranty Web Site and/or go Why is my Upright Deep Cleaner Foaming? Answer: What formula are you using? We recommend only using BISSELL Upright Deep Cleaning formula. Make sure you aren't using any manual formula in the machine because it will foam over. Related Questions My Spot Lifter Cordless machine seems to have reduced suction. What can I do to remedy this situation? My Lift-Off® Deep Cleaner isn't heating water well or at all. What should I do? My machine sprays through the flex hose but not the floor. Why is this? My ProHeat 2X® won't stop spraying. What can I do?