Most false alarms come from sensor placement and pets. Pet-immune PIR motion sensors ignore animals under a certain weight (often around 20 to 25 kg) when mounted at the right height. Avoid pointing sensors at windows, heaters, curtains or fans, keep them away from direct sunlight, and use door contacts and sensors in places pets cannot reach. Good installation prevents most false alarms.
Key takeaways
- Pet-immune sensors ignore small animals when mounted correctly.
- Sunlight, heat and moving curtains cause false alarms.
- Mount at the recommended height and angle.
- Use door contacts where pets roam.
- A professional survey avoids most false alarms.
01What triggers false alarms
| Cause | Fix |
|---|---|
| Pets walking past a sensor | Pet-immune sensor and correct height |
| Sunlight or heat on the sensor | Move it away from windows and heaters |
| Curtains or fans moving | Re-aim or move the sensor |
| Low batteries | Replace on the panel's warning |
| Loose door contact | Re-fix the contact and magnet |
| Insects or spiders on the lens | Clean and seal the sensor |
02Placement tips
- Mount where the burglar must cross, not where pets sleep.
- Follow the height and range in the manual.
- Use stay mode at night so downstairs sensors do not trigger while you move around.
- Test after installation by walking and by letting the pet walk.
- Re-check after moving furniture.
03Troubleshooting help
See burglar alarm not working and the burglar alarm guides.
04Frequently asked questions
Do pet-immune sensors work for big dogs?
They are rated for animals up to a stated weight; a large dog may still trigger them, so use door contacts or keep the dog out of the covered area.
Why does my alarm go off at night?
Often a sensor in the sun, a fan or curtain, or a low battery; we inspect and fix.
Can I bypass a sensor temporarily?
Yes; panels let you bypass a zone, but fix the cause.
Should I use stay mode?
Yes; stay mode leaves the downstairs sensors on while upstairs sensors are off.
