Open the dryer door approximately 90 degrees to reveal the screws holding the hinges to the body of the appliance. Tighten the screws by turning them clockwise if the door has begun to sag and is difficult to latch. You might find the dryer is difficult to start if you are unable to close the door.
Tighten the screws connecting the hinge and the door as well as all the visible screws around the edge of the door. If the panels of the door are allowed to separate or work loose the door will become awkward and rattle.
Apply a dab of silicon-based grease to the hinges; open and close the door a few times to work the material in. The door hinges squeak if the lubricant applied during construction runs out. If you cannot find silicon-based grease at your local hardware store you can use vegetable or canola oil.
Clean up any threads or lint trapped around the doorframe, particularly around the hole where the metal strike on the inside of the door enters the dryer. Tighten the strike if there is a screw holding it in place. Debris from clothes can work its way into the latching hole and cause an error to appear on the dryer's display.