# Garage door won’t close: check the safety sensors Updated: 2026-10-24 · https://pros411.com/en/guides/garage-door-repair/garage-door-wont-close ## Short answer If your garage door won’t close, look at the two safety sensors near the floor on each side of the door. Move anything in the way, wipe both lenses with a soft cloth and check their small lights. If one is off or blinking, loosen its wing nut, aim it at the other sensor until the light stays steady, and tighten it. Then press the wall button. ## How to get a garage door to close again ![Cartoon garage door that won’t close because a box blocks the safety sensor beam](https://pros411.com/img/guias/garage-door-wont-close.webp) 1. **It goes down, then right back up.** You press the button, the door starts down and reverses. The opener light may blink. Something is blocking the sensors, or they are out of line. 2. **Look at the little lights on the sensors.** Each sensor, low on both sides of the door, has a small light. Steady on both means the beam is fine. Off or blinking on one means trouble. 3. **Clear the path and wipe both lenses.** Move boxes, bins, bikes and leaves out of the doorway. Wipe each lens with a dry, soft cloth: dust, cobwebs and water spots can block the beam. 4. **Line up the sensor until its light stays on.** Loosen the wing nut, aim the sensor straight at the other one and stop when its light stays steady. Tighten the nut without moving it. 5. **Press the button: the door closes.** Watch the door all the way down. If it still reverses and the light blinks, check the sensor wires for cuts or loose staples. ## Why the sensors stop the door The two sensors send an invisible beam across the doorway, about 6 inches or less above the floor. If anything breaks the beam while the door goes down, the opener sends it back up. That is a safety feature. A bumped bracket, a dirty lens, a cobweb or strong sun shining into one sensor can set it off too. ## Need it closed right now? On many openers, you can press and hold the wall button until the door reaches the floor. Keep holding it the whole time and watch the door. Let go if anyone gets near. The remote and the keypad will not close it while the sensors are blocked, so fix them afterward. ## What not to do - Do not tape the sensors together, mount them up high or remove them. They keep the door from closing on a child, a pet or a car. - Do not spray cleaner straight onto the lenses. A dry, soft cloth is enough. - Do not pull the sensor wires tight or staple through them. A pinched wire can make the light flicker. ## When to call a garage door technician - The sensor lights stay off or blinking after you clean them and line them up. - A sensor wire is cut, chewed or loose. - The door still reverses with both sensor lights steady. - The door closes but does not reverse when something is in the way. Find garage doors in your city: https://pros411.com/en/garage-door-repair ## Frequently asked questions ### Why won’t my garage door close all the way? Most often the safety sensors near the floor are blocked, dirty or out of line, so the opener sends the door back up. If both sensor lights are steady, the door may be hitting something on the floor or need its down limit adjusted. ### How do I know if my garage door sensors are misaligned? Look at the small lights on the two sensors. Both steady means they see each other. If one is off or blinking, that sensor is out of line or something blocks the beam. ### How do I close my garage door if the sensors are not working? On many openers, press and hold the wall button until the door reaches the floor. Watch it the whole time and keep people and pets away. Then fix or replace the sensors. ### Can sunlight affect garage door sensors? Yes. Strong sun shining straight into one sensor can blind it, often at the same time every day. A small shade over that sensor usually fixes it. ### Can I bypass my garage door sensors? Not for good. Holding the wall button closes the door when you need it, but the sensors are what stop it from closing on a person, a pet or a car. Fix them or have them replaced. ### What color are the lights on garage door sensors? It depends on the brand. Many have an amber light on one sensor and a green light on the other. What matters is that both stay steady, not blinking.