I finally found that hidden door sensor that was driving me nuts

Had a job last week where the homeowner swore the back door sensor was working, but the panel kept showing it as faulted. I spent almost 3 hours checking the wiring, the magnet gap, even swapped out the sensor itself. Turns out the old installer had buried the reed switch behind the trim with drywall mud over it, no joke. The wire was pinched and shorting out inside the wall. Any of you run into sensors that were literally hidden inside the finish work like that?

2 comments

2 Comments

jones.angela5d ago

Got a similar one a few years back where the previous guy actually embedded the sensor magnet inside the door frame and then painted right over the whole thing. Took me forever to find it because it looked like just a normal chunk of wood. The kicker was the door was a solid core so the magnet was barely registering through the material anyway. Your mileage may vary but I swear some installers just do the weirdest stuff to hide wires and then act like it's normal.

davis.linda5d ago

Three years ago I found an old alarm transformer living behind a baseboard heater, completely buried in cobwebs and soot. It was still live at 16 volts, just dangling there with wire nuts barely holding on. The guy who installed it had literally cut a notch out of the drywall and shoved the transformer inside the wall cavity, then taped a piece of cardboard over it like that was fine. No box, no cover, nothing.