Possible Causes:

The dial on the heat sealer is not be turned up high enough. In order to seal the F57 Filter Bag, the dial must be set at approximately "4." In order to seal the XT4 Filter Bag the dial must be set to approximately "6." Different lab conditions may effect the proper setting. Experiment with a bag to "dial in" the correct setting.

The heating element is broken. On the sides of the Teflon cover on the heater sealer are two shiny metal strips that keep the cover in place. Loosen the screws that keep the strips tight to the base of the heat sealer and remove the Teflon cover. Check to see if there is a break in the heating element. If there is, take the extra heating element that comes with the heat sealer and replace the defective element. Additional elements can be ordered from ANKOM Technology (SKU: 1917).

The Insulator is not properly installed. The insulator should be installed to ensure that the heating element does not touch any of the metal on the base of the heat sealer.