What the Weather Here Does to It
Most garages around Lake Zurich sit on concrete poured decades ago, and that slab moves
We're in a cold-moderate climate band, which means the ground freezes and heaves every winter and settles back every spring. That cycle doesn't stop at the slab edge - it works on the thin metal brackets that hold your safety sensors to the bottom of each track, usually about six inches off the floor.
Those brackets get bumped by snow blowers, bikes, and salt-crusted boots all winter
But the freeze-thaw cycle is what actually shifts them over time, even if nobody touches them. A bracket that's off by even an eighth of an inch can point the sensor's beam just high enough, or low enough, to miss its partner across the opening. You won't notice until the door refuses to close, or worse, reverses on something that isn't actually there.
Houses here went up anywhere from 1938 to 2009
With most of the stock dating to the 1980s and 90s. That matters because sensor brackets from that era were often screwed straight into painted wood trim instead of the garage's structural framing. Wood trim swells and shrinks with humidity and cold far more than the stud behind it, so the sensor mount moves even when the door track itself hasn't shifted at all.
Doing Nothing For Now
If your door still closes on command and reverses when it should, you don't need to do anything today. Sensor misalignment is usually gradual, not sudden, so a door that's working fine this week will likely work fine next week too. There's no part here that fails catastrophically overnight the way a spring can.
That said, "working for now" and "aligned" aren't the same thing. A sensor pair that's barely catching each other's beam - lined up at the edge instead of dead center - will throw false faults the first truly cold morning, when the metal brackets contract a little more than usual. If your opener has ever refused to close for no obvious reason and then worked fine five minutes later, that's usually the tell. It's not broken yet. It's drifting.
The Problem
The actual failure mode is almost always one of two things: the bracket has rotated slightly on its mounting screw, or the screw itself has loosened in swollen wood trim and let the whole unit sag. Either way, the two sensor eyes - one sends an infrared beam, the other receives it - stop pointing at each other squarely.
Most openers show this as a blinking light on the wall control or on the sensor housing itself, but plenty of owners never notice the blink and just assume the opener is failing. It's worth checking the sensors first, because realigning two brackets takes a few minutes with a level, while diagnosing a logic board or motor issue on a false lead wastes a trip.
On older stock here - closer to the 1938 to 1985 end of what we've got - we also sometimes find sensors mounted to a block of wood that's no longer flat, because the slab underneath has settled unevenly over 40-plus years. In that case, realignment holds for a while and then drifts again, because the real problem is the mounting surface, not the bracket.
When to Get Help
Call if you've tried squaring up the brackets by eye and the door still won't close consistently
Or if the sensors look aligned but the light still blinks. At that point it's either a wiring issue at the bracket or a receiver going bad, and neither is a confident DIY fix.
We'll also say plainly
If your garage was built before the 1980s and the sensor mount is screwed into deteriorating wood trim rather than framing, realigning the bracket is a temporary fix. The honest answer in that case is a new mounting point, not another round of nudging the same loose screw. We won't keep charging you to re-align something that's going to drift again in a month.
If the household depends on one working garage door
Common across the owner-occupied houses in this area - it's worth having it checked before a cold snap rather than during one, since contraction in freezing weather is what usually turns a minor drift into a door that won't close at all.
