I recently received a phone call from a homeowner in Deltona whose door would not go down unless he held the wall button in until the door closed completely.

I told him that it was a built in safety feature of his operator. The safety sensors would not allow the door to close unless they were properly aligned and there  was nothing in the way. He checked his sensors and found a rag had fallen on one of the sensors and blocked the lens. Once the rag was removed the door operated fine and he saved himself a service call.