Proper safety sensor installation is key to a safe, hassle free garage door system.

Poorly installed safety sensor mounting brackets are one of the top reasons for misalignment, which results in Failure to Close.

In order to comply with code UL-325, your garage door safety sensors must be no more than six inches above the ground.  Eight inches above the ground used to be allowable, but the code was changed over 10 years ago.  There is no longer a minimum height.  This code is intended to prevent entrapment of a child, but neglects a very common situation — lots of things that can interfere with your garage door closing, especially vehicle bumpers, are more than 6” tall and will not be caught by the sensors.

The root cause of chronic safety sensor problems is usually one of two things:  either a poorly installed mounting bracket, or a bad wiring splice.

There is no good reason for problems with a spliced wire, especially if your garage door opener was professionally installed.  Anybody that owns a pair of wire strippers (you can use pliers or diagonal line cutters, too) can easily splice wires the right way, if they follow my instructions.  The thing about bad splices is that they often don’t act up until years down the line, as a result of the affects of moisture, oxygen, temperature cycles, being bumped, etc.

Installing the mounting bracket can be a bit more challenging, especially when the installer is a homeowner who doesn’t have the right tools.  In a lot of garages there is no option for a UL-325 compliant installation that doesn’t involve anchoring to the concrete or cutting enough away to make space for the sensors to bolt directly to the track.  This can be a daunting task without the right tools for drilling or chipping concrete.  It is best done with a rotary hammer, an expensive tool that a lot of people don’t have.

Here is a common situation

(pic of high concrete)

A bad mounting bracket installation is one that moves around, or is not installed in compliance with UL-325.  Some of the common bad safety sensor mounts we see are:

• Too high, usually when there is a concrete wall right next to the door that is taller than 6”. Many homeowners (and garage door technicians, sadly) do not have the tools, such as a hammer drill and masonry drill bit, to attach directly to the concrete.  Instead, they screw it into the wall just above the concrete.  I often see safety sensors installed several feet above the ground.
• Mounted to the concrete wall instead of the floor.  Over time gravity will do its thing and the sensors will come out of alignment as the anchors loosen.  It’s also an awkward angle to work on, making it much harder to mount the so it is aimed well.
• Mounted over broken drywall. It is fine to mount your safety sensors over drywall, as long as it isn’t all busted up and there is solid wood behind it for your screws to hit. If the drywall is broken it should be removed so you can attach directly to the wood.
• Mounted to drywall with nothing solid behind it. Even with drywall anchors, sensors that are mounted to drywall without catching the wood behind it will not hold up to being bumped, which is pretty much inevitable.
• LiftMaster/Chamberlain/Craftsman safety sensors that are clipped onto the track without a bolt to prevent them from popping off, which can happen if they get hit but sometimes seems to happen on its own for no apparent reason. As I have already detailed, the mounting brackets that come with Chamberlain manufactured openers are a terrible design that leads to a huge number of service calls for garage doors that won’t close.  I go into more detail here.
• Genie safety sensors that aren’t screwed into the wall all the way. Genie safety sensors come out of the box with long, thick, coarse threaded screws that don’t run into wood very easily.  To make matters worse they require either a flat headed screwdriver that will slip off the screw head, or a ¼” nut driver, which a lot of people don’t have on hand.  Good luck trying to run one of these into wood with a standard drill  or by hand with a screwdriver.  It’s better to discard the screws that come with it and use a standard Phillip’s Head construction screw instead.
• Loose concrete anchors. Over time, expansion and contraction from temperature changes can cause them to loosen.  Most of the time this can be fixed by gently tapping on them with a hammer to tighten them down better.
• Safety sensor brackets that are bolted directly to track that wiggles around when the garage door closes. Loose and/or improperly spaced vertical track can move around as the garage door gets close to the floor, breaking the connection between the safety sensors.  This may be easy to remedy, but there could be something else going on with the door that requires training and experience to identify and fix.
• Sensors that are installed in a spot that receives extremely bright, direct sunlight. This may be impossible to avoid in some garages, but luckily it usually only lasts for a few weeks out of the year.  Once the sun moves to a different position in the sky, this problem should resolve on its own.  The best thing to do is think about where the sun will be at its brightest and avoid putting the receiving sensor there.  In some garages the sun will still be a problem no matter what you do, but there are a few things you can try that may mitigate the problem for the few weeks out of the year that it is an issue.