Skip to main content

The 7 Most Common Reasons for Smoke Detector False Alarms

Apr 04, 2019|

Nails on a chalkboard. Grinding teeth. All the cringe-worthy sounds in the world can't hold a candle to the screech of a smoke detector that sounds for no apparent reason.

Has your smoke detector gone rogue? The sound of the alarm is designed to catch your attention, but if it's happening when there's no actual emergency, this can be both frightening and frustrating.

The good news is you don't have to go on living this way. A smart smoke detector provides reliable protection for you and your family in the event of a fire.

How smoke alarms work

Before we begin, it's helpful to know how smoke detectors work so you can determine what may be the cause of the false alarms in your home.

There are two primary types of smoke alarms: photoelectric and ionization.

Photoelectric smoke detection uses a steady beam of light. Once smoke particles enter the internal chamber of the device, the particles scatter the beam and redirect it to a photocell, which then triggers the alarm.

Smoke Detector Mounted White Ceiling
When it comes to smoke alarms, there are two main types: photoelectric and ionization.

Ionization smoke detection employs the use of ions and electrons that whizz around electrodes. When smoke enters the ionization chamber, it sticks to the ions, which disrupts the chemistry and activates the alarm.

Both types of smoke detection will activate when smoke enters the chamber; however, both are susceptible to malfunctions. Such malfunctions can be a result of poor manufacturing, smoke detector sensitivity, or external factors that can disrupt the performance of the device and trigger false alarms.

What can cause smoke alarms to go off repeatedly?

Here are seven of the most common causes of smoke alarm malfunction.

1. Smoke detector placement

It doesn't take a lot of smoke to trigger the alarm. If your smoke detector is within 10 feet of a cooking appliance such as your stove, toaster, or toaster oven, then this may be the cause of your false alarms.

Some of the more high-tech photoelectric smoke detection devices (i.e. the Vivint Smoke Detector) are even capable of detecting a sudden rise in temperature.

Installing your smoke detectors beside a window or door is also a common culprit in causing nuisance alarms. The draft can interfere with the performance of the sensors, even causing the illusion of smoke with particles that have drifted in from outside.

Smoke Detector Isolated
A photoelectric smoke device like Vivint's CO Detector will provide the best protection for your family.

2. Overcooked food

Does your smoke detector taunt you every time you slightly overcook your food? This could be a problem that has to do with your smoke detector sensitivity.

If your alarm is installed more than 10 feet away from your cooking appliance, but it still sounds every time you crisp your toast, you may want to test and adjust the sensitivity of your alarm. See how to adjust the sensitivity.

3. Steam or high humidity

High humidity carries dense moisture particles that your smoke detector may confuse for smoke particles. In extreme cases, the air is dense enough to scatter the light beam of a photoelectric sensor or cling onto the ions in an ionization chamber.

The same concept applies to steam. So, if your smoke detector sits right outside a steamy bathroom, you may want to move it to a different location.

Shower Head Running Water
Is your smoke detector right outside a steamy bathroom? If so, you may need to move it to prevent false alarms.

4. Pesky insects

Take a look at your smoke detector. Do you see the chamber entrances where smoke can enter? They’re just big enough to fit a small insect.

Once inside, insects can set off the alarm by interfering with the sensors. You may want to open up your smoke detector to see if there’s a pesky nuisance crawling around inside.

5. A buildup of dust

A buildup of dust can also affect your smoke alarm For this reason, experts recommend cleaning your smoke detectors with a vacuum brush attachment at least once a year–if not more.

6. Strong chemicals nearby

Smoke detectors are also sensitive to particles in the air that are released by strong-smelling chemicals. If you’re remodeling your home, deep cleaning, or using strong chemicals for another reason, this may be a cause of your false alarms.

7. The batteries need to be changed

Is your smoke alarm emitting a harsh, prolonged scream or a repetitive high-pitch beep? If your smoke detector is beeping, it’s informing you that the batteries need to be changed. Unless you’ve chosen an alarm that runs on a lifelong battery, you’ll need to replace the batteries at least once a year.

How to test your smoke detector's sensitivity

There are several ways to test your smoke detector sensitivity:

  • Buy some calibrated smoke detector test spray. Follow the instructions included with the product to ensure proper testing and accurate results.
  • If your alarm came with a testing instrument issued by the manufacturer, you can use this to conduct your test. Follow the instructions in the manual that came with your device. If you no longer have access to the manual, you may be able to find the information online.
  • Enlist the help of a professional technician to perform a test with the help of fire alarm control equipment.

Smoke Detector Wood Ceiling Closeup
If you want to test your smoke detector's sensitivity, check out any instructions you have from the manufacturer.

How to adjust a smoke detector's sensitivity

Adjusting the sensitivity of a smoke detector should be done with caution. The last thing you want is to inhibit the detector’s ability to detect traces of smoke.

For this reason, try these first two suggestions before moving onto the third.

  1. Relocate the device to put more distance between it and your cooking appliances or a steamy bathroom.
  2. Carefully remove the smoke alarm, open it up, and gently clean the inside with a soft, dry cloth. Reattach the alarm and vacuum the chambers with the brush attachment on your vacuum.
  3. If you have a programmable smoke detector, follow the instructions provided by the manufacturer to adjust the smoke detector sensitivity. This usually involves the removal of the data card and some simple modifications.

How to adjust smoke detector sensitivity

Hopefully, you were able to discern the cause of your false alarms from the list above. But if you’ve determined that your alarm is going off due to a problem with the smoke detector sensitivity, here's how to adjust it safely and effectively.

What to do when your smoke detector is too sensitive

As annoying as an overly-sensitive smoke detector may be, it's still a key part of your home’s security. You may be tempted to take it out or turn it off, but before you do, try modifying the sensitivity.

The experts at the National Fire Protection Association suggest testing the sensitivity of your smoke alarms every other year after the first test. A truly dependable detector with consistent readings can go longer (up to five years) without needing another test.

Let’s be neighbors.

Subscribe to our weekly newsletter for more smart tips.

Top 5 Security Essentials Ebook

Download our guide to home security.

Home is everything, so protect it. In this free guide you’ll find the information you need to create a safer, more secure home with the added convenience and comfort that come with smart automation.

Upgrade your smoke detection system

Often, the best option is to upgrade your smoke detection system. It's common for older smoke alarms to weaken and malfunction over time. The best way to stop abrupt false alarms without impairing the security of your home is to replace your old detectors with new models.

You can even take the opportunity to level-up your smoke detectors. Smart smoke detectors from Vivint, for example, work flawlessly even when the power goes out. These detectors communicate directly with your smart home system, notifying you on your smartphone when battery power is low or if there's been a spike in the temperature of your home. Plus, with a photoelectric sensor and a detection radius of 35 feet, you can count on Vivint smoke detectors to keep your home safe.

And in case of a fire, your alarms will sound inside your home and your Vivint system will alert our 24/7 monitoring specialists immediately. Next, your smart thermostat will cut off air flow to slow the spread of the fire and your smart locks will unlock automatically so you can evacuate and allow emergency personnel access to your home.

If you're not home, you'll get an alert on your smartphone that the smoke detector went off and our monitoring specialists will contact you right away, and contact the fire department if necessary.

Vivint app Smoke Detector Notification
If your smoke alarm does go off, you'll receive an instant notification via the Vivint app.

When smoke alarms are integrated with an entire smart home system, you'll enjoy peace of mind–whether you’re away on a business trip or playing with the kids in the backyard.

Ready to install a Vivint security system in your home? Call us at 844.481.8630 today for a free quote.

Get a free quote today.

A Vivint Smart Home Pro will contact you within 24 hours. Or skip the form and call now: 844.481.8630.

By clicking "Start Your Quote", you agree by electronic signature to:
1. The Electronic Disclosure Consent;
2. Receive recurring marketing communications from Vivint at the telephone number and email address you provide on this form, including autodialed calls, texts, and prerecorded messages (consent not required to make a purchase; reply “STOP” to opt-out of texts or “HELP” for help); and
3. Vivint's Terms of Service and Privacy Policy.

*Offer Details

Qualifying system purchase requires minimum $599.99 expenditure on equipment after all discounts have been applied, professional installation, and execution of Vivint monitoring services agreement. Click here for monthly service plan prices. DIY system purchases and reactivations of previously-installed systems not eligible for offer. Offer not available in all states or provinces. Equipment purchase may be financed separately subject to an agreement with one of Vivint's third-party financing partners. Monthly $1.48 cellular network maintenance fee applies. Taxes and local permit fees may apply.

Third-Party Financing Options Available

Financing eligibility and terms subject to credit approval by one of Vivint's third-party financing partners. Qualified customers may finance equipment purchase at 0% APR for up to 60 months. Month-to-month service agreement available when equipment is purchased upfront.

Vivint Systems & Services

System supports up to six cameras subject to sufficient WiFi speeds. Without a Vivint services plan, product and system functionality is limited (including loss of remote connectivity). Speak to a Vivint representative at the phone number in this offer for complete equipment, services, and package details, including pricing and financing details. Products and services in Louisiana provided by Vivint Louisiana Commercial Certificate #58280. See Vivint license numbers here.