First, verify that your appliance is plugged in and turned on by the power button. Make sure when you are ready to seal you press the Push to Vacuum and Seal Bar on both sides. Also, if the Removable Drip Tray is filled the vacuum will not start; you will instead see the Dry and Moist Feature flash a light indicating to clean it out and dry it off. Note if the Red Seal light is on you will not be able to vacuum, you would need to wait till it goes off.