Smart smoke and CO detectors are critical safety devices. This guide helps you troubleshoot common issues while ensuring your home stays protected. When in doubt about a safety device, replace it.
False Alarms
Alarm Goes Off While Cooking
- Location matters: Don't install within 10 feet of cooking appliances
- Use the "hush" button to temporarily silence during cooking
- Improve kitchen ventilation (run the range hood or open windows)
- Consider a photoelectric sensor for areas near kitchens—they're less sensitive to cooking smoke
Alarm Goes Off for No Apparent Reason
Common causes of false alarms:
- Steam: Bathroom steam, humidifiers, or hot showers nearby
- Dust: Accumulated dust inside the sensor chamber
- Insects: Small bugs can trigger the sensor
- Aerosols: Hairspray, air fresheners, cleaning sprays
- Low battery: Some detectors chirp or alarm when battery is dying
- End of life: Detectors should be replaced every 7-10 years
Cleaning the Sensor
- Remove the detector from its mount
- Use a vacuum with a soft brush attachment around all openings
- Blow compressed air into the sensor vents
- Wipe the exterior with a dry cloth (no water or cleaners)
- Reinstall and test with the test button
Detector Won't Connect to WiFi
During Initial Setup
- Most smart smoke detectors only support 2.4GHz WiFi—not 5GHz
- Check that you're entering the correct WiFi password
- Move your phone close to the detector during setup
- Ensure Bluetooth is enabled on your phone (many use Bluetooth for initial setup)
- Try temporarily disabling 5GHz on your router if you have a combined network name
Keeps Disconnecting
- Check WiFi signal strength at the detector's location
- Detectors on ceilings may have weaker signal—consider a WiFi extender
- Ensure your router isn't blocking the device (check MAC filtering)
- Some mesh networks cause issues—try connecting to the main node
Chirping or Beeping
Single Chirp Every 30-60 Seconds
This usually indicates low battery:
- Replace the battery immediately (don't just remove it)
- Use the battery type specified by the manufacturer
- After replacing, press the test button to confirm
- If chirping continues with new battery, try a different brand of battery
Chirping After Battery Replacement
- Make sure the battery is installed correctly (check polarity)
- Reset the detector: remove battery, hold test button for 15 seconds, reinstall battery
- The battery drawer must be fully closed
- Try another new battery—the first one may be defective or old
Chirping with Hardwired Power
- Even hardwired detectors have backup batteries—check and replace it
- Power interruption may have triggered a fault—reset the circuit breaker
- Check all interconnected detectors—one bad unit can cause others to chirp
Five Chirps Indicates End of Life
Many detectors chirp five times to indicate they've reached end of life (7-10 years). This cannot be silenced—the detector must be replaced.
App and Notification Issues
Not Getting Alerts on Phone
- Check that notifications are enabled in the app settings
- Verify phone notification permissions for the app
- Ensure the detector shows as "online" in the app
- Check that Do Not Disturb mode isn't blocking alerts
- Critical safety alerts should bypass DND—check app settings
App Shows Detector Offline
- Check WiFi connection at the detector's location
- Power cycle the detector (for battery units, remove and reinsert battery)
- Restart your router
- Hardwired detectors may need a circuit breaker reset
Multiple Detectors Not Staying Synced
- Ensure all detectors are on the same WiFi network
- Check that interconnect feature is enabled in app (if applicable)
- For wired interconnection, verify the interconnect wire is properly connected
- Remove and re-add detectors to the app one at a time
CO Detection Issues
CO Alarm Sounds with No Apparent Source
Important: Always take CO alarms seriously—CO is odorless and deadly.
- Get everyone outside immediately
- Call 911 or your local emergency number
- Do not re-enter until emergency services clear the home
After emergency services confirm it's safe, common CO sources include:
- Gas appliances (furnace, water heater, stove)
- Running car in attached garage
- Portable generators or grills used indoors
- Blocked chimney or vent
- Neighbors' CO entering through shared walls
CO Sensor Reading Seems Wrong
- CO sensors have a limited lifespan (typically 5-7 years for the sensor itself)
- Check the manufacture date on the unit—replace if expired
- CO sensors can be affected by hydrogen gas (some cleaning products)
- If you suspect a faulty sensor, replace the unit—don't risk it
Testing Your Detector
Monthly Testing
- Press and hold the Test button until the alarm sounds
- The alarm should be loud and clear
- If it sounds weak, replace batteries (or the unit if still weak)
- For interconnected units, test should trigger all connected detectors
Test Didn't Trigger Other Detectors
- Check interconnect wiring (for hardwired systems)
- Verify all units are on the same WiFi network (for wireless interconnect)
- Some systems require all detectors to be the same brand/model
- Test each detector individually to find the faulty unit
Installation Issues
Optimal Placement
- Every bedroom: One detector inside each sleeping area
- Every level: At least one per floor, including basement
- Hallways: Outside sleeping areas
- Ceiling or high wall: Smoke rises—mount within 12 inches of ceiling
- Away from: Windows, doors, HVAC vents (airflow affects detection)
Where NOT to Install
- Within 10 feet of cooking appliances
- In bathrooms (steam causes false alarms)
- In garages (exhaust fumes cause false alarms)
- In attics or crawl spaces (temperature extremes)
- Near ceiling fans or air vents
When to Replace
Replace your smoke detector if:
- It's more than 10 years old (check manufacture date on back)
- It chirps consistently even with new batteries
- It won't respond to the test button
- It has visible damage, discoloration, or contamination
- The CO sensor is more than 7 years old
Contact Support
Contact the manufacturer if:
- Device is malfunctioning within warranty
- You need help with interconnection setup
- Smart features aren't working after trying all troubleshooting
First Alert support: 1-800-323-9005 or firstalert.com/support
Safety reminder: Never disable a smoke or CO detector. If false alarms are a problem, move it to a better location rather than removing batteries or disconnecting it.