The three usual causes, in order: the safety sensors near the floor are misaligned, blocked, or blinded by direct sun on the receiving eye; something is actually in the sensor path, including a cobweb or a leaf; or the door's travel and force settings no longer match a door that has grown heavier or rougher with age, so the opener reads normal resistance as an obstruction. Sensor alignment is a five minute check. If the door is also loud, crooked, or heavy by hand, the reversal is a symptom, and the door, not the opener, needs the visit.
Prefer to talk later? Leave your details and an independent local pro will call you back. No charge to you, no obligation.
Park River Garage Door Co is a free referral service. Submitting this form connects you with independent local contractors who provide the work.