WARNING! TO REDUCE THE RISK OF SERIOUS INJURY OR DEATH! Checking proper operation of your garage door opener is extremely important and should be done once a month. Always keep your remote away from children and never let children play with door controls. Keep moving door in sight and never race under a closing door. Never go under a partially opened door, weak or broken springs may allow the door to fall rapidly causing serious injury or even death. Always disconnect the power cord before making any repairs. Garage door openers today have many features to ensure they will work safely. All openers are required to have a safety reverse system .to make sure your safety reverse system is working properly, put a box in front of your garage doors path and using your remote or wall control try to close the door. If your door closes, call a qualified service tech if your door does not close, your safety reverse system is working .now there is the down force adjustment. This adjustment allows the opener to close the door with the proper amount of force and still be safe to your family. By placing a 2 x 4 piece of wood on the center of the floor, face down in the garage doors path .the door should reverse when it comes in contact with the wood. If it does not, call a qualified service tech. if your door reverses on the wood you have a properly adjusted garage door opener.