Why Your Smoke Detector Gives False Alarms

May 01, 2017

There’s nothing more annoying than hearing your smoke alarm go off… and there’s no smoke or fire.

Has this happened to you?

This “false alarm” can be caused by issues that have nothing to do with smoke or fire. Your alarm may be going off unnecessarily due to one of these 5 common issues:

1. Humidity
2. Dust and insects
3. Strong chemical odors
4. Your detector’s location
5. Power issues

Note: these causes all trigger a full-blown alarm sound, not the small chirping noise you hear when you have low batteries.

In this article, we’ll go into detail about each of these causes and how you can solve them. So don’t worry, you’ll get rid of that annoying sound in no time!

Cause #1: Humidity

High humidity can cause a smoke detector to go off because the detector can mistake humid air for smoke. We’re especially susceptible to this problem in Florida where humidity is often 70% or higher, Ionization smoke detectors are most likely to mistake high humidity for smoke. Ionization is an outdated technology that was commonly used in smoke detectors before 2003. The problem with ionization is that it easily mistakes the bigger particles present in humidity (and dust) for smoke, thereby causing false alarms.

Solution: Close your windows and doors to block the outside humidity from reaching the smoke detector. Also, make sure your detector is 10+ feet away from rooms with high humidity like bathrooms and laundry rooms.

If you have an older ionization smoke detector, try switching it to a photoelectric smoke detector or photoelectric/heat detector combo to reduce false alarms from humidity.

Here’s how to tell if you have an ionization or photoelectric smoke detector:

• Step 1: Safely remove your smoke detector.

• Step 2: Look for these key indicators on the front, back or inside of the smoke detector (visit the section on that website, "How Do I Tell Which Smoke Alarm I Have?"). Generally, a photoelectric smoke detector will have the letter "p" or the word photoelectric on the back of the detector. An ionization detector will usually have an "i" or say ionization.

Cause #2: Dust

Dust that finds its way into your smoke detector can trigger the alarm because the detector mistakes those particles for smoke.

Solution: Remove your smoke detector and clean it to remove debris or dead insects. Also, see the solution for Cause #1 about switching from an ionization smoke detector to a photoelectric smoke detector.

Cause #3: Strong chemical odors

Have you painted your home or polished your furniture recently? In addition to agitating our nostrils, these strong chemicals like ammonia and paint can also set off your smoke detector.

Solution: Avoid using strong chemicals in areas that are close to your smoke detectors. If you do need to paint or use chemicals with ammonia, be sure to properly ventilate your home.

Cause #4: Your detector’s location

Some areas in your home can trigger your smoke detector’s alarm. You’ll want to make sure your smoke detectors are...

• 20+ feet away from appliances like your oven, furnace, and fireplace
• 3+ feet away from air conditioning and heating vents
• Not inside your garage. Automotive fumes or strong chemicals can set off the alarm, so we’d recommend going with a heat alarm inside your garage instead.

Cause #5: Power issues

Power issues that could cause your alarm to activate include the following:

• Power interruptions: AC/DC smoke alarms may go off briefly until your power comes back on.
• A loose hot wire: You’ll need an electrician to tighten the wires if this is what’s tripping your alarm.
• A large current load on the same circuit as your alarm: High wattage appliances like vacuum cleaners, space heaters or hair dryers that are on the same circuit as your alarm can overload your circuit, trip the power, and cause your alarm to go off. Avoid putting too many high wattage appliances on the same circuit as your smoke detectors.
• An interconnected alarm system: You’ve heard the phrase “one rotten apple spoils the whole bunch,” right? Well, the same applies to an interconnected alarm system, where all of your smoke detectors are all on the same electrical currents. If one goes off, they’ll all go off. If you’re having problems with false alarms, contact an electrician to change your alarms to separate units.

Is your alarm still causing you to lose sleep?

If you’ve tried some of those solutions and you’re still hearing your alarm go off, it could be that you just have a malfunctioning smoke detector or another electrical issue. You can try replacing the smoke detector yourself, but you should contact an electrician if the false alarms persist.

Have more questions? Or want a professional’s assistance?

Contact Energy Today to schedule an electrical repair. We’ll send one of our licensed electricians to your home to diagnose and repair your smoke detector.

We’ve been serving Florida families since 1963.

Posted in: Troubleshooting