When you turn the timer on the heat comes on, but when you hit the start button nothing happens. I don't remember the heat coming on before just when I turned on the timer.

Have you checked that there's nothing stuck in the dryer this happened to me - called the dryer guy who found a button had become stuck in the front of the dryer between the dryer and the door I couldn't see it but he could cause he was tall (its on the wall ) just check that there nothing stuck in it clean the filter and goodluck

If this is an elc dryer . U need to replace the heating elament . What is happing is that the elc heating elamint has a spring/coil that gets red hot and sits on ceramick insulators . Your coil is touching the case it sits in . And is going hot to ground .