If your gate opens fine but won't close – or starts to close then goes back open – nine times out of ten it's the safety sensors. That's actually them doing their job: they stop the gate closing if they think something's in the way. Here's how to work out what's going on.
What the sensors do
Most gates have photocells – a pair of small boxes facing each other across the driveway, one sending an invisible beam and one receiving it. If the beam's broken while the gate is closing, the gate stops and reopens.
Many also have safety edges – rubber strips on the gate or post that stop the gate if it touches something. Some newer systems use radar or other detectors too. You can read more in photocells, safety edges and sensors explained.
Common symptoms
- The gate opens but won't close.
- The gate starts to close, then stops and reopens.
- The gate only closes if you hold the button down (some systems allow this as a fallback).
- The gate works some days and not others – often worse in bright sun or heavy rain.
Safe checks you can do yourself
- Look for something in the beam. Wheelie bins, a parked car, overgrown hedges, a planter or even a spider's web across the lens can block it.
- Clean the lenses. Wipe both photocell covers with a soft damp cloth. Dirt, moss and condensation are common culprits here.
- Check for low sun. In autumn and winter, low sunshine straight into the receiver can confuse it. If the gate only plays up at a certain time of day, that's a big clue.
- Check they still face each other. A photocell knocked by a car, a mower or the bin can end up pointing the wrong way. Many have a small light that shows when they're lined up – don't force them, just note if one looks out of line.
- Wireless edges and photocells. Some use batteries. If yours are wireless and it's been a few years, low batteries could be the cause.
What not to do
Please don't disconnect or bypass the sensors to get the gate closing again. I see it done, and it's dangerous – it's the sensors that stop a gate closing on a child, a pet or a car. A gate with its safety devices disabled is no longer safe to use.
Leave the wiring and control board alone too. Once you're into the electrics, it's a job for a qualified engineer.
When to call me
Give me a shout if:
- the gate still won't close after you've cleaned and checked the photocells
- a photocell is damaged, loose or full of water
- the gate is reversing on its own with nothing in the way
- you think a safety edge is damaged or not working
I'll test the sensors, find the fault, and fix or replace what's needed. I repair all the major brands, including FAAC, CAME, BFT, Nice, Beninca and Chamberlain LiftMaster. See brands I repair.
Call, text or WhatsApp Adrian on 07855 781433.
Questions people ask me
Why does my electric gate open but not close?
Usually because the photocells think something's in the way. Check nothing is blocking the beam, then clean the lenses.
Can sunlight affect gate sensors?
Yes. Low sun shining straight into the receiver can stop the gate closing at certain times of day. I can often reposition or shield the photocell.
Can I bypass the photocells?
No – please don't. They stop the gate closing on people, pets and cars. If they're faulty, get them repaired.
How much does it cost to replace photocells?
It depends on the system. Often it's a simple swap, and I'll give you a price before doing anything.