Ensure that you have placed the handheld on the valve of the zipper bag or container BEFORE pressing handheld button. Make sure your built-in Handheld Sealer is properly placed over Valve of Bag or Container and held in position. Double-check that gaskets are not damaged; this may cause a leak in the Vacuum Chamber resulting in lack of proper Vacuum pressure. Make sure to always hold the handheld device in the upright position while in operation. It is designed with a “float” mechanism to stop the flow of air if an excessive amount of liquid is pulled into the reservoir. Turning the handheld on its side or upside down can cause this float to activate, blocking the vacuum port so that the air will not be removed from the bag or container.