If your dryer does not heat, but everything else is working, the problem is most likely the heating element. Replacing the heating element is an easy repair you can do yourself in a short amount of time with just a few common tools.
Unplug the dryer and move it to a large open area where you can work on it. Lay the dryer down on its front side on the floor. Most front load dryers have a heating element that is in the back of the dryer -- but check your owner's manual to make sure.
With a screwdriver or a nut driver, unscrew the back panel of the dryer, which usually has 10 to 12 screws. Gently remove the cover and set it aside. The heating element should be about a foot above the bottom of the dryer. This square box varies in size, but it will have coils inside that look like small springs.
Remove the two screws holding the heating element in place. Disconnect the two wires, or electrical connectors, attached to this box. Label the wires so you will know how to reconnect them.
Inspect the box to see if any of the inside springs are loose or broken. If they are, you need to replace the heating element.
Purchase a replacement heating element at your local appliance dealer. Be sure to take the serial number and the make of the dryer with you.
Place the new heating element in the dryer, being careful not to drop it. Reconnect the two wires according to how you labeled them, so they fit exactly as they did in the old heating element. Secure the screws to make certain the heating element does not move.
Replace the back cover panel and tighten the screws. Place the dryer upright and back into position against the wall. Plug in the dryer and turn it on. You should have heat. Let the dryer run for a few minutes to break in the new heating element.