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 Lift-Off® Deep Cleaner with HeatWave Technology® doesn't heat the water. What's wrong? The belt on my Big Green Deep Cleaning Machine® keeps falling off. What should I do? My DeepClean Essential® is continously spraying. What should I check? My brush stopped rotating. What could be wrong?