Two hours on a door contact that was loose, not broken

Spent a whole afternoon chasing a fault on zone 4, swapped the sensor, rewired the panel, still showed open. Turned out the magnet was just sitting too far from the reed switch, like 3/4 inch off. Has anyone else fought a simple gap issue for way longer than it should take?

1 comments

1 Comment

the_robin12d ago

Man, that's the classic one that gets you every time. What I never hear people mention is checking the magnet polarity or how the magnet is mounted in the first place. Recessed magnets can flip around if they're not secured tight, and a loose one will drop that gap from 1/4 inch to 3/4 inch without you noticing. I always stick a business card between the magnet and the door frame as a rough gauge now, if it slides in too easy, that's the problem.