How to test your opener safety reverse, step by step
A step-by-step monthly safety reverse test for a garage door opener, using a 2x4 laid flat, plus a photo eye check and what to do if the door fails.
Your opener should reverse a closing door when it meets an obstruction, and manufacturers and CPSC advise testing that every month. The test takes a few minutes. It is only for a door that is undamaged and working normally.
Before you test, check the door
Do not test a damaged door
Do not run the test if the door is crooked, off its track, hanging lower on one side, sticking, or if you heard a bang or see a gap in a spring or a frayed or slack cable. A door in that condition can fall. Do not use the opener or the manual release on it. Stay clear and have a technician inspect it.
The test closes the door under power. That is safe only when the springs, cables, tracks and rollers are working. If anything about the door looks or sounds wrong, skip the test and read when a garage door is unsafe to use.
Keep children and pets out of the garage during the test, and keep your hands, feet and body out of the door's path.
Why the test matters
Automatic openers have to reverse a closing door that meets an obstruction. CPSC issued federal rules for openers, and it advises owners to test the reversing feature monthly. Chamberlain states that its safety reversal system must be tested every month, and DASMA tells owners to make monthly inspection and testing of the door and opener part of a regular routine.
UL says the standard requires at least two entrapment protection mechanisms: the inherent reversal system, and either a photo eye or an edge sensor. This guide tests both. Without a working reversal system, Chamberlain warns that people, especially small children, can be seriously injured or killed by a closing door.
The contact reverse test
This tests the opener's ability to reverse when the door touches something. Your opener may have model-specific steps, so check your model's manual too.
- Make sure the opener is connected to the door and the door is fully open. If you released the door with the manual release, reconnect it first, as DASMA's guide describes.
- Lay a 2x4 flat on the floor, centered in the door's path. Chamberlain's page says the door must reverse on a 1-1/2 inch high object, and a 2x4 laid flat is the board DASMA names.
- Stand clear of the door's path, to the side, where you can see the door.
- Press the wall button to close the door.
- The door should stop and reverse when it meets the board. DASMA says the door should reverse direction on contact.
- Remove the board, then run the door through three or four full open and close cycles, as Chamberlain suggests.
The photo eye test
Photo eyes are the two small sensors near the floor on each side of the door. DASMA says they should be no higher than six inches above the floor. This check confirms that breaking the beam stops the door.
- Make sure both photo eyes are clean, facing each other and showing their indicator lights as your manual describes.
- With the door open, wave an object in front of the photo eye and then try to close the door with the remote or the wall button.
- DASMA says the door should not close unless the wall button is manually held during operation.
- If the door closes normally with the beam blocked, stop using the opener and see garage door safety sensors not working.
Indicator light colors and flash patterns differ by brand and model, so check your model's manual. Do not disconnect the sensors to get the door to close.
What a pass and a fail look like
| Result | What it means | What to do |
|---|---|---|
| Door stops and reverses on the board | Contact reversal is working | Repeat monthly |
| Door stops on the board and does not reverse | Contact reversal failed | Stop. Chamberlain says to adjust down travel per its guides and repeat, and to get a technician if it still fails |
| Door pushes the board or crushes it | Contact reversal failed | Stop using the opener and bring in a technician |
| Door closes with the photo eye blocked | Photo eye check failed | Stop using remote closing and have it inspected |
Chamberlain advises retesting after any adjustment and after repairs to the door, including springs and hardware, the garage floor, or the opener. If the door will not reverse after repeated adjustment, Chamberlain says to get professional service.
When to stop and bring in a technician
- The door fails either test, or you have to keep adjusting settings to make it pass.
- The opener has no photo eyes. UL dates mandatory photo eyes or equivalent devices to 1993, so a missing set means the opener may lack current protection. See repair or replace an opener.
- The door feels heavy, needs two hands to lift, or will not stay partway open. DASMA says this is a likely balance problem for a trained door systems technician.
- You see any damage to the door, track, spring or cable.
DASMA says a trained door systems technician should adjust the opener's sensitivity setting and the components tied to spring tension. Our technicians inspect the door and opener together, confirm the cause, and repair the sensors and openers. See opener repair and safety sensor repair. For more on how the system works, see auto-reverse explained.
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If something on your door looks damaged, stay clear and let a technician handle it.
Questions and answers
How often should I test the safety reverse?
Monthly. CPSC advises monthly testing, Chamberlain says the safety reversal system must be tested every month, and DASMA recommends monthly checks.
What do I use to test the reverse?
A 2x4 laid flat in the door's path is the object DASMA names. Chamberlain says the door must reverse on a 1-1/2 inch high object.
My door stops on the board but does not reverse. Is that a failure?
Yes. Chamberlain says to adjust the down travel following its guides and repeat the test, and to call a trained technician if it still fails. Check your model's manual for the adjustment.
Should I test after repairs?
Yes. Chamberlain says to retest after any adjustment and after repairs to the door, springs, hardware, floor or opener.
Can I test a door that sticks or looks crooked?
No. Do not run a damaged, crooked or off-track door to test it. Stay clear and have a technician inspect it.
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