Guide
Why Your Kent Garage Door Sensors Keep Drifting Out of Line
Kent Garage Door Co explains why safety sensors drift out of alignment on garage doors in Kent, WA homes built 1962-2005, plus what fixes it fast for good
Local detail
What It Costs
We're not going to hand you a number here - we don't publish a fixed price list for sensor calls, and quoting one without seeing the door would be a guess. What we can tell you is what drives the bill. On the houses that went up around here between 1962 and 2005, the sensor brackets you'll find are almost never original to the door - most were bolted on later, after an opener was swapped, and the mounting varies a lot: sheet-metal tabs screwed into old jamb wood, brackets shimmed with washers, brackets epoxied to a slab that's shifted a little every winter since it was poured.
A straightforward re-aim, where the eyes just need turning back to face each other, costs a lot less than swapping a cracked bracket or running new low-voltage wire because a trimmer or a rodent got to it. If the bracket has rusted through or the jamb wood around it has rotted - more common toward the older end of that 1962-2005 build window - that's a bracket-and-wire job, not a five-minute fix. Ask for the number before the truck leaves the yard, not after.
The area
What to Check
Before you call anyone, look at three things. First, the lenses - one on each side of the track, low to the floor. Wipe both with a dry cloth; dust and cobwebs are the single most common reason the light blinks and the door won't close, especially on the low-set doors common on houses from this area's 1962-2005 building era.
Second, check the brackets holding each sensor. In neighborhoods where most homes date from the 1980s and 90s, those brackets are often small L-shaped pieces of bent metal, and decades of the door banging shut can walk them out of true a degree at a time - you won't see it happen, you'll just notice one day the light isn't lined up anymore. Third, check that nothing is leaning against or near the sensor eyes: a bike, a bin, a coil of hose.
If the LED on one eye is solid and the other is dark or flickering, that's an alignment problem, not a dead sensor. If both are dark, check the wire nuts at the opener head before you assume the sensor itself has failed - connections like that loosen with age just like everything else on a decades-old install.
What we find
The Situation
Kent sits among a stretch of housing where the stock skews the same way across the board: median build year 1983, with most of it going up between 1962 and 2005, and that pattern holds across the 43 named areas that make up this part of the county. That matters for sensor calls because a lot of the openers on the market here aren't original to the house - they've been swapped once, sometimes twice, since the door itself went in, and each swap means a new set of holes drilled for a new bracket, at a slightly different height and angle than the last one. Across the service area there are roughly 228,944 households and 118,902 owner-occupied houses, and the ones built in that 1962-1983 stretch are the likeliest to be on their second or third opener by now.
A retrofit sensor bracket that was square when it went in during a spring install years back can walk out of alignment slowly enough that nobody notices until the door refuses to close. It isn't dramatic. It's a slow drift, not a sudden failure, which is exactly why most people don't catch it until the door won't shut at dusk and they're standing in the driveway aiming a phone flashlight at a sensor eye.
How we work
What the Weather Here Does to It
This area sits in a cold-moderate climate band - not brutal winters, but enough freeze and damp most months to work on anything mounted outdoors. Sensor brackets are usually bare or thinly painted metal, sitting a few inches off a concrete slab that stays cold most mornings from fall through spring. That swing, slab cold against a bracket warmed a little by afternoon sun, drives tiny expansion and contraction over years - not enough to notice in one season, enough to matter over the fifteen or twenty years a bracket's been bolted to an older house.
Damp mornings also fog the lenses themselves, and a lens with a film of condensation reads to the opener the same as a blocked lens: door won't close. On mornings right at the edge of freezing, that fog can sit on the glass for close to an hour after sunrise. None of this is a repair issue by itself - it usually clears on its own - but if you assume a sensor is broken because the door won't close before 8am and then works fine by 9, that's the cold-moderate climate doing it, not a bad part.
Questions
Common questions
Why does my garage door sensor light blink but the door still won't close?
Nine times out of ten it's a dirty lens or a bracket that's drifted a degree or two out of true - common on the retrofit brackets found on houses built in the 1962-2005 era around here. Wipe both lenses, check nothing's blocking the beam, and look at whether one LED is solid while the other blinks. That points to alignment, not a dead part.
Is a drifting sensor a sign I need a new opener?
Not usually. Sensor drift is almost always a bracket or alignment issue, separate from the opener motor itself. We don't have pricing to quote without seeing the specific bracket and wiring, but replacing a bracket is a much smaller job than replacing an opener.
How often should I check sensor alignment?
Check it each fall and spring, since the cold-moderate swings here work slowly on outdoor brackets over the freeze-thaw months. If your house is from the 1962-2005 building stretch common in this area, the bracket is likely a retrofit, which drifts more than a factory-original mount.
Ready when you are
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Kent Garage Door Co repairs and installs garage doors, springs and openers in Kent, WA and the surrounding area.