If your dryer is not heating, takes way too long to dry clothes, or will not turn on, then you may need to replace the Dryer Thermal Fuse.
Pull the dryer away from the wall. To prevent electric shock, unplug the dryer from the wall. Using a screwdriver, remove all of the screws holding on the back panel.
Once you remove the back panel, the thermal fuse is located on the blower housing. Remove the two wire terminals and the screw. The thermal fuse has a little tab on one end and you have to pivot it out.
To install the new fuse slide the open end with the notch, put the screw back in place and reattach the wire terminals.
Using a screwdriver, reattach the screws holding the back panel. Plug the dryer back into the power outlet and push the appliance back against the wall. Test the dryer to make sure it will turn on and is heating properly.