Just Serviced and Now It Reverses: Post-Service Decision Tree

Why this matters

A door that reverses on closing right after a service visit is the most common garage-door callback. The customer reads it as "you broke it." In nine cases out of ten the reverse is the opener doing exactly what UL 325 requires: it sensed a force or beam interruption and refused to crush something. The fix is not to disable the safety, it is to find what changed during the service that pushed force, balance, or sensor alignment over the limit. This tree keeps you from chasing the wrong fault and protects you from a citation or a warranty claim.

Step 1: Recreate the failure

Watch the door close from inside the garage. Note exactly where in travel the reverse triggers:

• Reverses immediately on press of close: the opener is reading an entrapment condition before motion starts. Photo-eye or wire fault.
• Reverses in the first foot of travel: friction high at the top of the door, force setting clipping early.
• Reverses in the middle of travel: spring balance off, friction in track or rollers, or photo-eye misalignment.
• Reverses just before fully closed: down-limit set past the floor, or seal bottoming early.
• Bounces on the floor then reverses: down-limit set too low.

Each location points at a different cause. Do not adjust until you know which one.

Step 2: Photo-eye check first

Before anything else, walk to the photo-eyes. They sit roughly six inches above the floor on each side. Both indicator LEDs must be steady, not blinking. Common findings after a service visit:

• One sensor knocked out of alignment by a ladder, foot, or hose.
• Sensor wire pinched under a fresh roller bracket.
• Sensor lens covered in dust kicked up during track lubrication.
• One sensor unplugged from a junction made during the visit.

Realign so both LEDs are steady. Run the door. If it now closes, photo-eyes were the entire fault and no force adjustment is required.

Step 3: Disconnect and balance test

Pull the opener release cord with the door fully closed. Lift the door by hand to about three feet of travel and let go. The door should hold position. Then lift to full open and check that it holds open without drifting closed.

• Door drops fast from the three-foot test: springs are weak or under-tensioned for the door weight. Re-tension or replace springs.
• Door drives up out of your hands at three feet: springs are over-tensioned, often from a fresh spring install sized for a heavier door.
• Door holds three feet but slams closed from full open: a single spring on a two-spring system has failed.
• Door is heavy through the whole lift: friction problem, not balance. Check rollers, hinges, and track.

Balance must be correct before any opener force adjustment. The opener is sized to overcome friction, not unbalanced spring weight.

Step 4: Track and roller friction

After balance is verified, re-engage the opener and run the door. Listen and watch:

• New rollers binding in track: the track may have closed up during the service or the new rollers are a tighter fit than the worn ones. Adjust track clearance to spec (typically 3/8 to 1/2 inch from door face to inside of vertical track at the top).
• Hinges installed in wrong positions: long-stem rollers on horizontal track, short stems on vertical, or top fixture incorrectly set. Re-check assembly.
• Track lubricant on the rollers themselves: rollers should never be lubricated on the wheel surface, only at the bearing. Wipe rollers and re-lube only at the bearings.

Step 5: Force adjustment

Only now, with photo-eyes correct, balance correct, and friction normal, touch the opener force settings. Force is not a band-aid for high friction or bad balance; it is the final calibration once the mechanical system is right.

Follow the opener manual for the model on the truck. Set down force to the lowest value that allows full close without nuisance reverse. Test by holding a roll of paper towels under the door at knee height during close: the door must reverse on contact within 2 seconds and travel back up at least to the half-open position. This is the UL 325 inherent reverse test.

If you have to raise force higher than mid-range to get close-without-reverse, something earlier in this tree is still wrong. Go back.

Step 6: Limit adjustment

The down limit must stop the door at the floor without pushing past it. A limit set past the floor causes the door to bottom and reverse on the down-force sense. A limit set short leaves a gap at the bottom seal. Adjust per the opener manual; small turns of the limit adjuster, retest after each.

Step 7: Verify the close-out tests

Before you collect payment, run the full sequence with the customer watching:

• Photo-eye test: wave a broom through the beam during close, door reverses fully.
• Down-force test: roll of paper towels under the closing door at knee height, door reverses fully within 2 seconds.
• Manual disconnect test: pull the cord, lift the door by hand, confirm balance.
• Up-stop and down-stop test: limits correct, no bounce, no gap.

All four must pass. Document the test results on the ticket.

References

• UL 325, Standard for Door, Drapery, Gate, Louver, and Window Operators and Systems
• ANSI/DASMA 102, American National Standard Specifications for Sectional Doors
• Door and Access Systems Manufacturers Association, Garage Door Inspection and Safety Guidelines