First off when you replaced the heat element there's 2 wires going to the moisture bars on the inside front of the unit i bet you didn't reattach those wires, it's a common mistake. Also clean those bars up with a piece of sandpaper or a metal bristle brush they get fabric softener and detergent residue that affects the moisture sensor cycle. Easy way to test if your moisture sensing is working properly, put NO clothes in unit run it for 10-15 minutes if it shuts off by itself it's working properly. Good luck