Door won't close? Keeps reversing? It's usually the sensors. St. Charles Door Pros provides same-day garage door sensor repair throughout St. Charles County, MO — alignment, replacement, and safety testing.
If your garage door goes down a few inches and then reverses back up — or won't close at all while the opener lights blink — the safety sensors are almost certainly the culprit. Every garage door opener manufactured after 1993 is required by law to have photo-eye safety sensors mounted near the floor on each side of the door opening. These sensors project an invisible infrared beam across the doorway. When something breaks that beam — a person, a pet, a box, or even a spider web — the door stops and reverses.
Sensor misalignment is the most common cause of unexplained door reversals in St. Charles County, MO. The sensors get bumped by lawn equipment, bicycles, or just shift over time from normal vibration. When one sensor points slightly off-axis, the beam doesn't complete the circuit — and the opener interprets that as an obstruction, refusing to close the door. Blinking lights on your sensors or opener are the tell-tale sign.
Do not bypass your sensors. It may seem like a quick fix, but disconnecting or taping over safety sensors is both dangerous and illegal. The sensors exist to prevent the door from crushing people, pets, and property — including your car. Call (636) 422-5849 for a fast, proper sensor repair in St. Charles County, MO instead.
The most common issue — the sensor eyes have shifted so they no longer face each other directly. We realign both sensors to factory specification and verify the beam is complete before leaving. This fixes most "door won't close" calls throughout St. Charles County, MO.
Dust, cobwebs, grime, or even condensation on the sensor lenses can interrupt the beam. We clean the lenses and check for positioning issues — a quick fix that's often overlooked.
Sensor wires run along the door frame and can be pinched, cut by lawn equipment, or develop loose connections at the terminal strip. We trace and repair wiring faults for all opener brands serving St. Charles County, MO homes.
When sensors are properly aligned and wiring is intact but the door still won't close, the sensor itself may have failed. We replace safety sensors for all major opener brands — LiftMaster, Chamberlain, Genie, Craftsman, and more.
Direct sunlight hitting the receiving sensor can overwhelm the infrared signal, causing intermittent failures — often only at certain times of day. We diagnose sunlight interference and can reposition or shade sensors to eliminate the problem.
After every sensor repair, we verify full operation by testing the auto-reverse function with a physical obstruction. You'll see the door work correctly before we leave — no guessing whether the fix took hold.
| Service | Typical Price | Notes |
|---|---|---|
| Sensor Realignment | From $75 | Includes safety test |
| Sensor Cleaning + Realignment | $75 – $95 | Full safety test included |
| Sensor Wiring Repair | $85 – $150 | Depends on wire run length |
| Sensor Replacement (pair) | From $125 | Parts + labor + safety test |
| Full Sensor + Wiring Replacement | $150 – $225 | All-in fix for older systems |
* Same-day sensor repair available throughout St. Charles County, MO. We confirm pricing before starting. Call (636) 422-5849.