All about smoke alarms and security lights

Alarms safeguard your property and can save lives, but you'll aggravate your family and your neighbours if they are not set up correctly. Most problems come down to issues of power supply or poor installation and are usually simple to fix. Here are a few solutions.

All about smoke alarms and security lights

The security light is faulty: adjust the sensor to stop false positives

Automatic security lights are usually triggered by infrared radiation (heat) from an intruder. They are also fitted with a light sensor that prevents the light operating during the day. Security lights need careful positioning and setting up if they are to work effectively. If the light is switching on and off for no apparent reason, ask yourself:

  • Is it being activated by people or cars moving past the house? If so, angle the unit downwards more to restrict its field of vision. Alternatively, you can select the area "seen" by the sensor by masking off parts of the lens with insulating tape. Masking the top of the lens will restrict long-range detection, for example.
  • Can the sensor "see" other heat sources, such as air vents or other security lights? If so, reposition the sensor accordingly.
  • Are there overhanging branches near the unit? They could trigger an alarm on a windy day, so trim them back.

Smoke alarm frequently goes off: reposition the alarm for optimum safety

Smoke alarms are sensitive devices. If you have positioned them carefully, they'll need only minimal attention to keep them working reliably.

  • Don't place smoke alarms in kitchens, bathrooms, garages or next to fireplaces. Fresh paint may sometimes trigger alarms, too, so be sure to air a newly painted room before considering that the alarm may be defective.
  • A regular chirping sound indicates the battery needs replacing — get and install a new one immediately. Don't remove the old battery until you are ready to install the new one — chances are that you'll forget to replace it once the alarm is silent.
  • Some alarms can be triggered by dust in the air and may sound when you do your spring cleaning. Open the alarm casing and vacuum the inside using the brush attachment to remove dust particles.


An erratic smoke alarm is dangerous, as it may fail to warn of a real fire. Test the unit every month and replace it if there's the slightest suspicion that it's faulty.

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