Gate motor keeps opening or closing by itself: what's triggering it

The pattern is the best clue. Watch the gate for a day or two, or ask whoever is home, and match it up:

A gate that closes on its own is nearly always doing what it was set up to do.

• Auto-close. Centurion, ET and Gemini motors can all close the gate automatically after a delay. On Centurion's D5-Evo and D10 it's off by default in the standard modes and the delay is adjustable; on Gemini's sliders it's set with small switches on the control card. In condominium mode, it's the only thing that closes the gate.
• Beam auto-close (PIRAC). Centurion and ET both offer a mode in which the gate closes as soon as your car has passed the safety beam, so nobody can follow you in. It can feel abrupt, but it's working as intended.

If the timing doesn't suit you, it can be changed at the controller. What should never happen is the gate closing on a car or a person: the closing beam is there to stop it, so if it does, stop using the gate and see safety beams.

Centurion's D5-Evo and D10 have a built-in clock, called ChronoGuard, that can open the gate by itself at set times: through the main trigger, the free-exit input or pedestrian opening. Up to 100 time-periods can be set, once off or repeating weekly or yearly, and the display shows a Tp icon while one is active.

It's a useful feature, for a domestic worker's arrival or a school run, for example, but it's easy to forget it was set, and a new owner may never have been told. If your gate opens like clockwork, ask whoever set the gate up, or ask us to look through the time-periods on the controller. ChronoGuard can also do the opposite, blocking an input at set times, such as switching off the free-exit loop after hours.

Complexes, estates and some homes have a free-exit loop: a coil of wire under the driveway, inside the property, that senses the metal in a car and opens the gate so you can drive out without a remote. Centurion notes that a person can't set it off, and that while the gate is already open, the loop only restarts the auto-close timer.

So a gate that opens every time a car approaches from inside is working. One that opens with no car near the loop points to something metal left on it or a loop detector fault, which are both technician work. Some estates use a beam instead of a loop for free exit; then anything that breaks it, including people, can open the gate.

When the gate opens with no pattern, the makers' own fault-finders point to the same short list:

• A trigger that's stuck on. The intercom's gate release, a push button in the house and a remote receiver all tell the controller to move the gate. A button stuck down, or a receiver set to hold its signal, leaves that input on, and Centurion notes that the input's light on the controller then stays lit.
• Damp in the wiring. Centurion's fault-finders list moisture on the trigger and free-exit inputs, and joints buried underground that collect water, as causes of spurious triggers. Gemini lists faulty push-button wiring. If the gate opens more after rain, suspect this first, and see gate motor after rain or lightning.
• Someone else's remote. Gemini's fault tables list a remote from your area learnt onto your board, and Centurion lists an outside remote with the same code, typically with DIP-switch remotes, whose code is set with tiny switches. An old tenant's or contractor's remote, still in the receiver's memory, does the same thing.
• A faulty receiver, or the controller itself, which the makers list last, once the rest are ruled out.
• The electric fence. Centurion's R3 and R5 fault-finder also lists a faulty electric fence among the causes.

If you have a GSM opener, anyone on its user list can open the gate with a call or the app. Centurion's G-ULTRA keeps a history log you can view in its app; see GSM gate openers.

• Account for every remote. Check the car's console, the cubbyhole and bags for a remote pressed by something else, and ask who else has one.
• Try the intercom's release button and any push button in the house: press each a few times and check it springs back.
• Note the times and the weather. "Every weekday at 07:30" and "after every storm" point to very different causes.
• Clear lost and unknown remotes from the receiver. The fix for an unknown remote is to erase every remote from the receiver and learn back the ones you have; see how to program a gate remote. If yours are older fixed-code remotes, newer code-hopping ones are worth asking about: see gate remotes.

Don't open the controller to look at its lights or wiring: it sits beside the battery and the power connections.

Centurion's manuals ask installers to check that a gate doesn't move on its own when left in any position, and ET's that it neither opens nor closes under its own weight. A sliding gate that rolls open by itself when the motor is released, or a swing leaf that drifts, isn't level: the rail has sunk, a wheel has worn, or a hinge has dropped.

That's a gate fault, not a motor one, and it also makes the motor work harder in one direction. Don't leave the motor released; lock it again so the gears hold the gate. More on rails and wheels is on sliding gates and swing gates.

If the gate keeps opening at night, holiday lockout is the tool for the job. On Centurion and ET motors it disables every input, so no remote, button, loop or stray signal can open the gate, until it's switched off with the lockout button. Two things to know: it only switches on with the gate closed, and while it's on, your own remotes won't open the gate either. ET's version isn't available in condominium mode.

How it's switched on and off differs by model: see the Centurion D5-Evo manual and the ET manual. If your remotes have no lockout button, or it doesn't hold, close the gate and call us.

Call us when the pattern points to wiring, a receiver, a loop or the controller, or when you can't find the cause. Tell us when it happens, what the weather was, and what make the motor is. We trace the signal, fix the joint or part that's sending it, and clear the remotes you don't want. All our spare parts are genuine, and every repair carries our six-month guarantee on our repairs. No call-out fee when we do the work. If no work is done, a R650 call-out fee applies.