Why does my smoke alarm keep going off?

This article contains the following sections:

  • Irregular smoke alarm sounds
  • Commonly found issues with smoke alarms
  • Common reasons for unexpected smoke alarm beeping

Important information to note

Got a beeping or chirping smoke alarm? Click here to try our troubleshooting tips.

If all that fails and the property you're residing in is enrolled in our smoke alarm safety service, please click here to request an urgent service. Alternatively, call 1300 134 563 and one of our customer service team members will be on hand to book an urgent appointment and may be able to offer some additional troubleshooting advice.

Most irregular smoke alarm sounds fall into two categories: either your alarm beeps at regular intervals (chirping), or beeps consistently without stopping (sirening).


Chirping is when the alarm beeps roughly once every 45 seconds – 1 minute. This is usually to indicate low battery power. Most of the time when this happens, the battery just needs to be replaced. If the alarm is a mains alarm, you might need to disconnect the alarm from its base or plug and remove the battery. Then hold the test button for 10 seconds to drain the alarm of residual power before putting a new battery in.


Sirening is when the alarm beeps consistently without stopping. This usually indicates smoke has triggered the sensor in the smoke alarm. For a detachable alarm, if it is sirening, it will most likely need replacing. For mains powered alarm, it will also likely need replacing

Other commonly found issues with smoke alarms

Flashing Red LED

This is completely normal across all alarms as long as there is no sound.

Flashing Green LED

On mains powered alarm, this is normal and simply means that it is connected to the mains power.


On mains powered alarm, this likely means that the LED light has simply stopped working. It may also mean the alarm is not connected properly to the mains, in which case, it will use the battery until it goes flat. The smoke alarm will need to be replaced or the wiring has to be checked to make sure power is connecting to the smoke alarm.

Alarm sirening

At least one alarm senses smoke. If no danger is present, press and hold test/hush button on triggered alarm for 5 seconds (where multiple alarms, identify triggered alarm by the flashing red LED). Alarm will resume operation in approx. 10 minutes.

Alarm chirping

Alarm may require cleaning. Refer to our smoke alarm troubleshooting tips.

Alarm chirping & flashing Red LED

Alarm requires new batteries.

Alarm flashing red LED intermittently

Alarm requires servicing.

5 common reasons for unexpected smoke alarm beeping

1. Maintenance

Your smoke alarm might be alerting you that it needs some attention—think of this as smoke alarm self-care! Smoke alarms typically have an end of battery/end of life warning built-in. Check the battery: is it running low? Check the expiry date: is it time to reinstall and update your hardware? Smoke alarms are only guaranteed to last 10 years, so be mindful of the date of installation. Organise for regular smoke alarm maintenance by a qualified provider, who should keep your alarms up to date and working so you don’t have this problem again.

2. Dirt

Where is your smoke alarm located? Dust, debris and even insects and spiders can work their way into the alarm and disrupt its normal operation. Any intrusions can interfere with the battery and cause your smoke alarm to beep. Make sure your smoke alarms and the areas around them are cleaned regularly, and keep creepy crawlies away. Once a year, your smoke alarm hardware should be thoroughly vacuumed as part of an annual service.

3. Fire

Never ignore a beeping smoke alarm! Even if you can’t see it or smell it, there could still be a fire. Smoke alarms can sense things that you can’t, which is why it’s so crucial to keep them in regular working order. If nothing else can explain the beeping, there could be an electrical or hidden fire that you can’t quite pick up. Be prepared to act in case of fire: Here’s a great guide to creating your home fire escape plan.

4. Steam

Smoke alarms are designed to detect the slightest interference. A properly-working alarm is so sensitive that steam or even humidity can set it off! Use bathroom fans when taking a shower, open windows or use a ventilation fan when cooking up a storm in the kitchen and use a microfiber cloth when cleaning your smoke alarms to absorb any moisture.

5. Something Burning

Detecting smoke is the smoke alarm’s job, so it’s no surprise that it goes off at overdone toast, burnt cooking or your neighbours’ wood fire. At least you know it’s working properly in the event of a real fire! Ventilate the area and the sound will stop when the smoke has cleared.


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