My corner mount sensor in a laundry room kept false alarming, figured out why

I put a motion sensor in a tight corner spot above a washer and it went off every 45 minutes like clockwork. Turns out the steam from the dryer was creating heat patterns right in its detection zone. Anyone else had humidity mess with their PIR sensors?

2 comments

2 Comments

gracewebb22d ago

I had the same issue with a sensor in my kitchen near the oven. Five years ago I set up a PIR in a corner above the stove and it kept tripping every time I opened the oven door. The heat plume from the oven vent would hit the sensor just right and trigger it. Steam and heat can definitely mess with those things, especially if they're mounted close to appliances that put out moisture or warmth. I moved mine about 3 feet to the side and aimed it away from the stove and it stopped false alarming completely.

owens.cameron22d ago

Gotta disagree with you on this one, @gracewebb. I've had a PIR sensor mounted right above my stove for almost 7 years now and it's never once false alarmed from heat or steam. The key is getting the sensitivity setting dialed in right from the start. Most people crank it to max out of the box and then wonder why it trips on everything. If you set it to medium or even low, it ignores small temperature changes like opening an oven door or boiling a pot. Moving it 3 feet sounds like overkill when a simple adjustment on the sensor itself would have fixed it. Maybe yours was just a bad unit or the placement was way too close to the vent, but I think heat triggered alarms are more about poor setup than a flaw in how PIRs work. I've tested this with my own setup by purposefully blasting steam from a kettle right at it and it never flinched because I had it tuned correctly.