why do smoke detectors beep at night

Wondering why do smoke detectors beep at night, or more accurately should they?

The smoke detectors should be completely silent all of the time.

That makes the alarm critical when it sounds and users shouldn’t be disturbed by constant “chirping” during the night.

Smoke detectors beep at night because the operation of the battery makes the device enter a “low-battery” beeping mode when the temperatures drop.

During the night, between 12 PM and 6 AM the temperatures drop low enough to produce this problem.

Why Do Smoke Alarms Chirp At Night?

why the smoke alarms chirps

As mentioned, the smoke detectors should be silent at all times.

The beeping always comes from the battery and when this “chirping sound” happens only during the night, there is a scientific answer to the weird occurrence.

When the battery charge is low, it forms an internal resistance, while the low room temperature increases that resistance.

The result is always the same – a low battery beeping mode.

In all cases, the beeping means that the battery of the smoke alarm device has to be replaced, which most certainly will prevent the device from beeping in the middle of the night.

Note: A smoke detector with a recently replaced battery should not chirp even in an environment with low temperatures.

More About The Nighttime Chirping!

Here are both types of smoke detectors and why they chirp during the night:

Wireless Smoke Detector Chirping At Night

The wireless smoke alarms are entirely dependent on the battery.

When the charge gets low, they enter the beeping mode, which makes them chirp every 60 seconds.

wireless smoke detector chirps in night

The issue occurs through the night, since the temperature drops.

Hardwired Smoke Detector Chirping At Night

Hardwired smoke detectors are quite different from wireless alarms. These devices are not based entirely on a battery, instead, they are connected to the electrical system of the building.

That makes the night-time chirping quite different.

When the battery of a hardwired smoke detector is low, the device won’t start to beep until there is power from the circuit breaker.

However, when the power is out during the night and the backup battery is low, even the hardwired smoke alarm will start to beep.

How To Prevent A Fire Alarm Beeping At Night?

prevent fire alarm from beeping

To clarify, the night chirping always comes from the device’s battery.

Even when the battery is not low enough to always chirp, when the room’s temperatures drop, the beeping mode will be activated.

There are quite a few things that will mute your smoke detector.

Replace The Battery!

Here’s how to replace wireless smoke detector batteries:

  1. Twist the device a quarter turn to release the device’s top cover.
  2. Locate and open the batteries, and cover them.
  3. Remove the old batteries and insert the fresh pair.
  4. Mind the polarity poles.

On some smoke detectors, the battery compartment has to be opened by a handle on the side of the device.

In such cases be gentle when pulling the cover to prevent damaging the device.

Reset The Alarm

You can reset the smoke detector and make it stop beeping for the time being.

To do so you need to take the device off the mounting bracket and disconnect the cable (if hardwired).

Remove the battery and hold the TEST button for 15 seconds.

reset alarm of smoke detector

This will trigger the alarm for a short time and then the detector should become silent.

Mind that the alarm is loud and piercing and wouldn’t be a good approach when there are other people sleeping in the same room/apartment.

Increase Room Temperature

The best and easiest way to prevent the beeping naturally is by increasing the room’s temperature.

Even a few degrees down, during the night, can increase the resistance enough for the device to enter the low battery mode, so it should be hard.

There are four different ways to increase the temperature:

  • Close open windows
  • Turn ON the heating
  • Prevent cold breeze 
  • Stop the Air Conditioning

Turn OFF The Device

turn off device

When you don’t have a replacement battery in the middle of the night and all you need is for the chirping to finally stop, you can simply stop the alarm.

That could be dangerous and would expose everyone inside unprotected in case of a fire hazard so do it at your own risk!

  • The wireless smoke detector can be turned OFF by taking the batteries out!
  • The hardwired smoke detector has to be disconnected from the AC line and then the batteries should be ejected as well.

When the device is OFF, there is no way that the beeping sound continues!

Note: Most people prefer a night full of chirping, rather than sleeping unprotected.

Smoke Detector Still Chirping At Night?

detector still chirping at night

In case the smoke detector continues to emit the chirping sound at night, even with a fresh pair of batteries, then the device has to be replaced.

The issue suggests that the device is not receiving enough power to function properly, therefore you’ll need to check the assembly date.

ALL smoke detectors have a sticker showing when the device has been manufactured.

The label is usually found on the bottom of the device so to unveil the sticker, you’ll need to remove the detector from the wall or the ceiling.

In case the alarm has been assembled more than 10 years ago, then you should definitely replace the entire smoke detector.

There is a misconception in regard to the 10 years. Not 10 years of usage, instead the device has to be replaced if 10 years have passed since it was assembled.

Alert: It’s not safe to utilize an old, malfunctioning smoke detector!

Will The Smoke Detector Chirp All Night?

will smoke detector chirp all night

The straightforward answer is no. The beeping should disappear as soon as the temperatures in the room start to rise.

You can attempt to increase the temperature by closing the opened windows or preventing a cold breeze coming from the outside from passing through the device.

Just a few degrees down are sometimes enough to trigger the chemical reaction inside the smoke alarm and make the device enter the “low battery” chirping mode.

In case you can’t stop the chirping at night, you should relocate the smoke alarm!

Note: The location of your smoke detector might be exposing the device to an airflow, making the device colder, hence, chirping.

Best Places For A Smoke Detector (No Chirping At Night)

best places for smoke detector

Now that we know why do smoke detectors beep at night you might be wondering what’s the best place where the device won’t beep in the middle of the night.

To prevent the smoke alarm from chirping at night you need to choose a suitable place for the device. 

You need to avoid places where cold air is flowing during the night: 

Such locations are near windows, close to the front door, or where the device is exposed.

The best place would be in the bedroom or in the corridor near the bedroom.

You need to make sure that the location has no flowing air during the night and that the temperatures are not dropping too much at night.

Tip: Close ALL doors before going to bed to prevent airflow, thus your smoke detector from beeping during the night.

Quick Recap:

Thus, the smoke detector is beeping during the night because the temperatures drop and the resistance in the battery increases.

When the device’s power is low the detector will be “chirping”, which are the exact conditions occurring during the night.

Final Thoughts:

We’ve learned why do smoke detectors beep at night and we can conclude that the positioning of the device plays a vital role.

When your smoke alarm won’t stop beeping during the night, it’s always better to replace the device and have peace of mind and good sleep.

We hope that this post was helpful and for more relevant guides, check our blog!

Nicole B