Ikea Motion sensor motion detected during the night


My Ikea motion sensor detects motion and starts some automation during the night, when nobody walks in front of this sensor.

I don’t know what is going wrong? I don’t find anything to modify sensibility or something like that. Any idea?

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False triggering of PIRs overnight is completely normal due to the cooling of air, furniture, etc causing heat movements that can appear to the thermal sensor as movement.

As batteries discharge they can also become more sensitive to temperature which is why 03:30 is the classic time for PIR (and smoke detector) issues.

Alarm system PIRs include logic to only trigger after several detections (double knock), but HA PIRs are designed to trigger straight away.

You could add a conditional to the automation, or try replacing the battery. As it is an IKEA sensor, I’d also suggest enabling automatic firmware updates in ZHA in the Z-Wave integration.

If this helps, :heart: this post!


Thanks for this great information!!!

I have 60% of battery,

But I can change in order to check if the percentage information is correct.
I didn’t know the existence of firmware updates in ZHA, is great! I will test it.

Is interesting that batteries are more sensitive to temperatures

Thanks for your support!

Although I agree in part with this statement, I do think it has a lot to do with the quality of the sensor. We have 12 motion sensors that are all hue sensors and have never had a single false trigger in nearly 3 years.

The ikea ones are both slow and rubbish, I’ve got a few left I’ve stuck outdoors for basic night time use, but I’ve moved all my indoor ones to Hue as above.

After comparing different bare PIR modules for Tasmota projects, there are definitely differences in hardware sensitivity.
The software also makes a difference with a trade-off between immediate triggering, and software “double knock” reducing false triggers but delaying your lights coming on.
Some multisensory have sensitivity settings (think Fibaro Z-Wave has - but mediocre battery life), but just as alarm systems moved to microwave + PIR, you can do the same.

One fix is to add door sensors to turn lights on immediately, and mixing PIR + microwave for occupancy (e.g. YouTube Everything Smart Home).

Thinking back to alarm system PIRs, you could try:

  • moving the sensor way from glass, windows and radiators.
  • point upwards (avoids pets),
  • add cardboard / stickers / alu foil to the sensor to mask off areas

Sadly, these are less likely to work with HA sensors as they are smaller and designed to trigger immediately.

Thanks for your advice! I’ve changed battery, and at this moment, I have a 100% of battery on that device, I will know if this is the problem. I’ve changed the location but the problem is the same, but I have a glass in front of the motion, I will try to change to a convenient location.


Thanks. Maybe If I can’t solve this problem, I can switch to a Hue motion sensor. I only want it with zigbee protocol.

Thanks! Maybe Hue sensors are better!

I think like most things in life, you get what you pay for, we certainly have no complaints and they are commonly shown to be some of the best on the market, although slightly more expensive than most.


Two days ago I’ve changed battery and I changed location… and it has worked!
Because I didn’t know witch change was the solution, yesterday I’ve changed device location to the old location, when I had the problem, and I don’t have any false detection!

It seems to me I need to test more days in order to confirm that, but I think change battery was the solution.

Thanks everyone for your support and ideas!

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I’m trying out an idea that might work in some situations.
I get some false alerts in my laundry & some of that can be from the washing machine or dryer but recently other unexplained instances too.
I happen to have two pir sensors in that room & they are in a group. So far i used the default option that turns on the group if either sensors is triggered. But i just changed that option to require both sensors to be triggered before the group is on & thus triggering lights.

Has the dual PIR worked out for you?

I still get some false triggers in the laundry. Now i also get some false triggers in other rooms too that interestingly also utilise the same Ikea PIR sensors. So in my case i think my issues are with my ikea sensors & its not related to how the sensor groups are configured.

I have experienced issues with sensor reliablity before when the battery gets low, even if the reported value seems good (60-80%) or if the battery is of poor quality. So my next step is to swap out some batteries to see if that makes any difference.

I was getting lots of false positives with the Ikea sensors… started writing increasingly complicated automations and bayesian sensors to deal with the issue. Recently, I replaced the Ikea sensor with a Sonoff zigbee motion sensor and have had no problems since.

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In my case, battery replacement was the solution.