Garage door won't close unless you hold the button? Check the sun

If your garage door won't close unless you hold the button, the opener is telling you the safety sensors cannot see each other. In October and November, the usual reason is not a broken part. It is the low sun shining straight into the receiving sensor, which blinds it the same way a beam blocked by a bike or a box would. The tell is the time of day: the door closes fine at noon and refuses in the late afternoon.

This is a fall question here. The sun sits lower in the sky every week until late December, and when daylight saving time ends on November 1, sunset in Colorado Springs moves to before 5 p.m., right when most people pull in and press the remote. Below is how to confirm it is the sun, how to fix it for good, and what else causes the same symptom.

What the door is doing, and why

Every opener sold in the US has two small photo eyes, one on each side of the opening, no more than about six inches above the floor. One sends an invisible infrared beam and the other receives it. If the beam is broken while the door is coming down, the opener stops and reverses. Holding the wall button down overrides that check, which is why the door closes when you hold it and not when you tap it.

Strong sunlight carries a lot of infrared. When it falls directly on the receiving eye, the receiver cannot pick out the sender's beam from the glare, so the opener treats it as an obstruction. On many openers the light on the motor unit flashes and the door goes back up or will not start down at all.

How to tell it is the sun

• It depends on the time of day. The door closes in the morning or after dark, and fails for an hour or two when the sun is low and in line with the opening.
• It started in the fall. A door that worked all summer and began acting up in October points at the sun angle, not at a part that wore out.
• The sensor light changes. Look at the receiving eye, which on most openers is the one with the green light, while sun is on it. If the light goes off or flickers and comes back when you shade the lens with your hand, you have found it.
• Shading it fixes it. Stand so your body shadows the receiving sensor and press the remote. If the door now closes normally, it is the sun.

How to fix a garage door sensor blinded by the sun

1. Shade the receiving eye. A short piece of PVC pipe or a cardboard tube slipped over the sensor, or a purpose-made sensor sun shield, keeps low sun off the lens without blocking the beam. It must not cover the lens itself, and it must not change the aim.
2. Swap the sensors side to side. Only the receiver can be blinded. If the sun always comes from one side, moving the receiving eye to the shaded side, and the sending eye to the sunny side, often ends the problem. On most openers both eyes run on the same two wires, but the brackets and wire routing have to come with them, and both eyes need to be re-aimed afterward.
3. Clean the lenses. Dust, cobwebs and dried water spots scatter sunlight across the lens and make glare worse. Wipe both with a soft dry cloth.
4. Re-aim both eyes. A sensor that is slightly off target has less beam to spare, so a little sun pushes it over the edge. Adjust until both indicator lights are steady, then tighten the wing nuts.
5. Replace old sensors. If the sensors are original to a much older opener, the lenses may be faded or cloudy. Replacement sensors have to match the opener's brand.

Two things not to do. Do not mount the sensors higher to get them out of the sun, because the six-inch height is what protects a child or a pet lying in the doorway. And do not bypass the sensors or wire them together. That removes the safety reverse completely.

Other reasons a door closes only while you hold the button

If shading the sensor changes nothing, the opener is still saying it cannot see the beam, just for a different reason:

• Something in the path. A trash can, a broom, leaves blown against the track, or snow packed against the bottom of the jamb.
• A sensor knocked out of line. A bumped bracket is the most common cause after the sun. The indicator light on one eye will be off or blinking all the time, not just in the afternoon.
• Wiring damage. A staple through the wire, a chewed wire, or a loose connection at the motor unit. Cold weather makes a cracked wire open up.
• The door is fighting itself. If the door stops or reverses even while you hold the button, that is not the sensors. It is the opener's force setting or the door itself: a stiff, frozen or worn part. Read our guide to why a garage door is loud in cold weather, and if you recently changed the weather seal, see how to replace a garage door bottom seal.

If the sensors check out and the opener still will not close the door on its own, that is garage door opener repair rather than a sensor adjustment.

The Colorado Springs part

• A lot of clear days. The Pikes Peak region gets far more cloudless afternoons than most of the country, so a sun-blinded sensor here fails day after day instead of once in a while.
• The sun drops fast in the fall. At midday in mid-October the sun is about 43 degrees above the horizon in Colorado Springs. By the winter solstice it is about 28 degrees. Every week it reaches deeper into a garage opening.
• West- and south-facing driveways. A garage that faces west takes the afternoon sun straight into the opening. One that faces south can get low sun for much of the day in December.
• Open, treeless subdivisions. Newer neighborhoods out toward Falcon and on the east side have little shade, so nothing breaks the sun before it reaches the sensor.
• Snow makes glare. After a storm, sun reflecting off a white driveway can blind a sensor at angles the direct sun would not.

When it is worth a visit instead

• The sensor light stays off or blinks even in the shade.
• You have shaded and re-aimed the sensors and the door still will not close on the remote.
• The door stops or reverses even when you hold the button.
• You would rather have the sensors moved, swapped or replaced, and the opener's safety reverse tested, by someone who does it every day.

The short version

A garage door that won't close unless you hold the button has safety sensors that cannot see each other. In the fall in Colorado Springs, the low afternoon sun shining into the receiving sensor is the most common cause, and the giveaway is that it only happens at certain times of day. Shade the receiving eye, or swap the sensors so the receiver is on the shaded side, then clean and re-aim both. Never raise the sensors or bypass them.

Frequently asked questions

Can the sun really stop a garage door from closing?

Yes. Sunlight contains infrared light, and when it shines directly into the receiving sensor it drowns out the beam from the sending sensor. The opener reads that as something in the doorway and will not close.

Why does my garage door only close when I hold the button?

Holding the wall button overrides the safety sensors. If that is the only way the door closes, the sensors are blocked, blinded by the sun, out of line, or have a wiring fault.

Which garage door sensor is the receiver?

On most openers it is the one with the green light. The sending eye usually has an amber or red light. Check your opener's manual to be sure.

Why did my garage door sensors start acting up in the fall?

The sun sits lower every week from late September to late December, so it starts reaching into the garage opening and onto the sensors at times of day it never did in summer.

Is it safe to move the sensors higher?

No. They belong about six inches off the floor so the door reverses for a child, a pet, or anything low in the opening. Shade the receiver or swap the sides instead.