Travel limits
Travel limits are the opener settings that define where the door’s journey ends in each direction — the fully-open stop and the fully-closed floor position. Set correctly, the door seals the floor without straining the mechanism; set wrong, they produce gaps, slams, or the classic close-then-immediately-reopen fault.
What the limits define, and how they interact with force
An opener has no eyes on the floor — it knows the door’s position only as travel distance from a reference. The two limits encode the endpoints: UP, where the door clears the opening without the carriage striking the motor head or the door over-running its horizontal track; DOWN, where the bottom seal compresses against the concrete just enough to close the gap without the motor continuing to push a landed door. Between the endpoints, travel is free; at them, the motor stops by instruction rather than by resistance.
The interaction with force limits is where diagnosis lives. A down limit set shy leaves a daylight gap under the seal — visible, annoying, benign. A down limit set deep converts landing into an obstruction event: the reversal that follows is the force system correctly protesting a travel error, which is why the two settings calibrate as a pair and why the commissioning sequence lands travel first, then tunes force, then proves both with the reversal test. Every "my door has a mind of its own at the floor" story resolves inside that pairing.
Limit symptoms, sorted
| Symptom | Which limit | Direction of the fix |
|---|---|---|
| Daylight gap below the seal | down, set shy | extend down-travel a fraction; re-test |
| Closes, then instantly reopens | down, set deep | walk the down limit back to a soft landing |
| Slams the floor audibly | down, deep + speed | shorten travel; check balance too |
| Stops short of fully open | up, set shy | extend up-travel; check for rail obstructions |
| Carriage bangs the motor head | up, set long | shorten up-travel before hardware pays for it |
| Seal wear stripes on the floor | down, grinding at rest | ease the compression; the seal should kiss, not grind |
The practical frames
Gaps are not always limits
A gap at one corner only — with the other side sealed — points at the floor or the door racking, not the limit setting. Limits move the whole door’s stop; geometry problems move one side. The pattern tells you which page you are on.
Landing quality is a spec
The commissioned finish: seal compressed to contact along its full width, no motor strain at rest, no reversal, no slam. If a service visit ends with any of those missing, the calibration is not done.
Relearning cycles are normal
Many modern units run a deliberate slow cycle after power loss while they re-find their endpoints. Let one complete before judging the settings — the odd behaviour often calibrates itself away.
The floor can be the mover
New epoxy coatings, settling slabs and winter heave all relocate the destination. When the floor changes, the down limit inherits the difference — a two-minute trim, once you know to look there first.
Travel limit questions
Why does my door touch the floor and then pop back open?
The down limit is set past the floor. The opener expects more travel than exists, so when the door lands early — by its own settings’ reckoning — the leftover push registers as an obstruction and the entrapment logic dutifully reverses. It is the single most misdiagnosed symptom in the opener world: it looks like a sensor ghost and is actually a stop-point set a fraction too deep. The cure is walking the down limit back until landing reads as arrival, not impact.
What causes limits to drift out of adjustment?
Time and mechanics, mostly. Chain and belt stretch shifts the carriage’s effective position; worn travel components change where the door actually lands; concrete settling or a new floor coating literally moves the destination. Electronic units can also lose calibration after power events and relearn on the next cycles. Drift is gradual and ordinary — the annual service visit re-lands the limits in minutes as routine calibration.
Can I adjust travel limits myself?
It is homeowner-accessible on most units — screw dials on older openers, button sequences on newer ones, manual by the model’s label or app. The honest caveats: down-limit errors interact with force sensing, so changes must finish with the 2×4 reversal test; and a limit that suddenly NEEDS large correction is usually reporting a mechanical change worth understanding first. Small seasonal trims, yes; chasing a moving target, book the visit.