How to test the garage door's auto-reverse
For a garage door auto reverse test, lay a 2x4 flat on the floor in the door's path and close the door. It should reverse when it touches the board. Then break the photo-eye beam while the door closes, and it should reverse again. If either test fails, disconnect the opener until it's fixed.
What a garage door auto reverse test checks
A garage door is heavy, and it keeps closing unless something tells it to stop. CPSC reports about 73 children between the ages of 2 and 14 were trapped and killed under automatic garage doors from March 1982 to the date of its fact sheet. Others suffered brain damage or serious injuries.
Two separate systems protect you, and a working door needs both.
- Contact reversal: the door senses resistance and backs up. CPSC requires this on all openers made or imported for US sale after January 1, 1991.
- External sensing: a photo eye or door edge sensor stops the door before it touches anything. This requirement was added in 1993.
First, check your opener's age. An older opener may have neither, and CPSC urges replacing those with a model that meets the federal standard. If you just bought the house, look for two small sensors on the door tracks near the floor. No sensors usually means an older unit or a different system, so read the label or have a technician look.
CPSC says to inspect the door and opener every 30 days. The trade group DASMA specifies a 2x4 laid flat because it stands 1.5 inches tall, the height the door must react to.
How to do a garage door auto reverse test
- Clear the area
Move cars, bikes and pets out of the way, and tell everyone not to use the door until you've finished.
- Open the door fully
Check the floor under the door is clean and that nothing is resting on the sensors.
- Lay the 2x4 flat
Set it on the floor across the door's path, on its wide side.
- Close the door
Stay clear with the wall button in reach. The door should reverse as soon as it touches the board.
- Test the photo eyes
Open the door, remove the board and start closing. Pass a long object through the beam. Keep your body out of the door's path.
- Check eye height
Measure from the floor to each sensor. CPSC says 4 to 6 inches.
- Check balance and hardware
With the door closed, pull the quick release and move the door by hand. Reconnect it when you've finished.
- Set a monthly reminder
Pair it with another recurring job, so it happens every 30 days or so.
Garage door photo eye test: how to read the results
| Test | Pass | Fail | What to do |
|---|---|---|---|
| 2x4 flat on the floor | Door reverses on contact | Door stops or keeps pushing | Disengage the opener. Adjust it using the manual, repair it or replace it. |
| Break the photo-eye beam while closing | Door reverses | Door keeps closing | Clean and realign the eyes and retest. If it still fails, stop using the opener. |
| Eye height | 4 to 6 inches off the floor | Mounted higher | Have them lowered. A child can fit under a high beam. |
| Balance, door released by hand | Lifts smoothly and stays put when partly open | Hard to lift, won't stay, binds or sticks | Call a professional. A badly unbalanced door can crash down. |
| Look at hardware | Springs, cables, rollers and pulleys look sound | Frayed cable, broken spring, damaged parts | Don't operate the door. Call a technician. |
A paper towel roll isn't a substitute for the board. DASMA notes it may not compress to 1.5 inches, so a door can pass that trick and still be unsafe.
What to do if your garage door won't reverse
A door that fails either reversal test isn't safe to run on the opener. CPSC says to disengage the opener until it's adjusted, repaired or replaced. Pull the quick-release handle only with the door fully closed, then use the door by hand. Releasing an open door can let it fall.
You can do the opener's own adjustments if the owner's manual explains them. Retest afterward. Leave anything under tension to a trained technician, including springs, cables and the brackets at the bottom of the door.
Finish with two small changes that reduce risk for kids. CPSC says to mount the wall button as high as practical, and to keep the remotes away from children. Tell kids plainly that the door isn't something to race or play under.
What homeowners say about testing garage door sensors
Testing auto-reverse is DIY, but leave the torsion springs alone. DIY regulars rank spring adjustment among the few home jobs that can seriously injure you. (DIY Stack Exchange)
2x4 garage door test questions
How often should I test my garage door's auto-reverse?
Monthly. CPSC says to inspect the door and opener every 30 days. The test takes only a few minutes and needs one board.
Why do you use a 2x4 for the garage door test?
Laid flat, a 2x4 is 1.5 inches tall, which is the height the door has to react to. Standing it on edge or using a soft object doesn't test the same thing.
Is it safe to keep using a garage door that doesn't reverse?
Not with the opener. Disengage it and use the door by hand, with the door closed when you pull the release. Have it adjusted, repaired or replaced before you reconnect it.
Sources: CPSC, dasma.com, doors.org
General guidance for U.S. homes, not professional advice. For gas, electrical and structural work, call a licensed pro.