Door heads down, then back up? Look at the sensors.

Signs this is your problem

• The door halts partway down and rises again, never touching the slab.
• It closes only while you keep a finger on the wall button.
• One sensor light blinks, or stays dark while the other glows.
• It started after someone pressure-washed the garage floor or the driveway.
• It started after water came into the garage in a storm.
• It reverses right as it touches the floor: that one is usually the opener's settings, not the sensors.
• The door hangs crooked: that's off track, not the sensors.

What trips them in a Naples garage

The sensors live close to the floor, so they get everything the floor gets. Spray from pressure-washing the slab or the driveway works into the housings and the wire splices. Beach chairs, golf bags and bikes leaned against the wall nudge a bracket a little off line. Sand tracked in after a day at the beach settles on the lenses. And when storm water reaches the garage, the sensors and their wires are the first electrical parts it touches.

Each of those looks like a failed part, and often the sensor is fine and needs cleaning, drying or aiming. Unsure it's the sensors at all? The symptom guide sorts it by what the door does. Door won't close and night is coming? The emergency line answers at any hour.

When it's the part, not the dirt

We test each sensor and the thin wire that runs up the rail to the opener, looking for a pinched spot, a staple through the insulation or a splice turned green by corrosion. A dead sensor gets swapped along with its mate, and the brackets are fastened firmly so the next bump leaves them where they are. If the wire sat in salt water, the whole run gets replaced, not just the sensor.

Before we leave, the door passes two safety checks: it closes onto a 2x4 lying flat under it and must reverse, and it must stop and go back up when someone steps through the beam.

Questions about safety sensors