I have only had this dryer for around 3 years and want to know if it is repairable. The heat will not engage at all and nothing else seems to be wrong with it?

Yes it's worth repair and cheaper if you do it yourself. Do you have more time or money? Neither, Right? After only three years I would not expect the ignitor to be bad, but we can't rule that out. A blown non-resetable thermal fuse is the likely culprit. When you have a restriction in the venting the temperature will rise and cause the fuse to blow. Take the back panel off and check for continuity across the thermal fuse (small white fuse with two wires) If you don't have test equipment tape the wires together and see if you get heat. Ta Da!