Motion detector night lights don't work in GFCI outlets?

General Questions
#1

I searched everywhere for this and can’t even find someone with the same issue.

I bought a motion activated night light for my bathroom. I plugged it into a GFCI outlet, and when I set the switch to motion-activated, it just stayed lit up.

I thought it was faulty, but the night light came in a two-pack. Same thing with the other light.

Not sure what made me check, but I tried them in regular outlets. They both worked.

I’m guessing there’s a great reason… what is it?

Thanks!

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#2

Something wrong with the outlet. Maybe missing ground, or reversed hot/neutral, or defective GFCI.

#3

Can you plug them in upside down?

#4

Did you wait for awhile? All the motion sensor night lights I have come on when first powered up and take 5-10 minutes to turn off and go into sensing mode.

Dennis

#5

I am assume there are just two prongs (hot and neutral) on the light?

Does the GFCI receptacle work O.K. with standard appliances (e.g. hair dryer)?

Yes, there’s a reason for it. But so far I have no idea what it is.

#6

Either I am misunderstanding the OP, or others are.

The outlet works fine. The GFCI does not trip. The night light works fine, except it stays on, never turns off, correct?

If both are doing the same thing, there maybe something in the bathroom causing them to stay on. My understanding on how these things work is that the sense heat, or actually, moving heat. So, for example, if you had a central heating or AC vent that blew across its “field of vision”, so to speak, it might turn it on. Or, if the wall directly across the room from it had a hot water pipe in it, it might turn on if you used the hot water (and caused the wall to heat up a little).

My last theory is that there is something in the geometry of your bathroom that is preventing you from “sneaking up” on it. That is, it “sees” you coming and turns on. Perhaps reflective surfaces or something else.

#7

The outlet works fine. When I plug the night light into the GFCI outlet, it stays on. I tried the night light in other non-GFCI outlets around the house. It goes off after a minute, and then comes on as soon as I walk up to it.

The water heater is directly behind the wall it’s plugged into. I have a small house, so the water heater is in the kitchen. The bathroom is on the other side of the kitchen wall.

I plugged the night light into a GFCI outlet in the kitchen that is not near the water heater. Same thing. The light comes on immediately, but never shuts off.

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#8

Do the GFCI outlets have an LED on them? If so, try blocking it with electrical tape or similar occlusive material.

I’ll speculate that the LED is strobing and throwing off the motion detection somehow.

#9

A passive infrared (motion) detector works by detecting a slight current differential. A GFCI operates with an electric coil to detect a current differential. (Normally the sum current through your two wires is zero).

I wonder if your symptom is caused by interaction between these two differential current detectors?

#10

One test you could run would be to cover the infrared sensor so that it can’t detect motion (test on a non-GFCI outlet), then plug it back in. If it still stays on in the GFCI, then you know it’s not some external stimulus that’s causing it to stay on.

#11

Another test, run an extension cord and put the light in the hallway to prevent the bathroom environment from interfering. I could imagine the mirror or the vent (and a passive irregular updraft being enough to trip the heat sensor).

#12

Or just get a regular 4-watt night light for the bathroom, and leave it on all the time.

#13

I tried that, which didn’t work.

Oh, well. It’s not necessary to have :slight_smile:

#14

I don’t know how a GFCI receptacle could possibly cause that behavior in the light. I’m guessing there is something else going on; for whatever reason the light is “seeing” motion all the time when it’s plugged into that receptacle.

#15

Does the wall vibrate slightly, say if an appliance is running or the water is one?