How To Identify Types Of Smoke Alarms
Shock your friends with this post.
Key Takeaways
- Look for a solid green light: it tells you the alarm is 240V mains powered.
- Battery alarms must be sealed: in the NT a battery type must be a sealed 10 year lithium unit.
- All compliant alarms are photoelectric: check the label on the alarm.
- Keep them clean: dust, cobwebs and moisture can cause false alarms.
How to Tell a Battery Smoke Alarm From a 240V Smoke Alarm
Do you know how to tell the difference between a battery and a 240V mains powered smoke alarm? Today we’re going to help and explain the difference and the easily identifiable features between the two types of smoke alarms, so that you can maintain the smoke alarms at your home effectively and reduce annoying beeps.
The easiest way to spot the difference between the two types of smoke alarm is to look for a solid green light on the smoke alarm head. A solid green light indicates the presence of mains power and that the smoke alarm is a 240V smoke alarm. A battery smoke alarm will not have a solid green light.
Battery vs 240V Smoke Alarms at a Glance
| Feature | Battery smoke alarm | 240V mains smoke alarm |
|---|---|---|
| Green light | No solid green light | Solid green light |
| Battery | Sealed 10 year lithium, cannot be replaced | 9V backup battery you can replace |
| When the battery fails | Replace the whole alarm | Replace the 9V battery |
| Installation | Fits to the ceiling base | Hardwired by a licensed electrician |
Smoke Alarm Battery Rules in the Northern Territory
In the Northern Territory, to comply with the smoke alarm legislation, a battery type smoke alarm must be a 10 year lithium battery and it must be sealed and inaccessible, meaning that the battery cannot be replaced.
A 240V smoke alarm will have a 9V backup battery installed within the smoke alarm head that can be accessed and replaced if the battery has failed or perished. As this type of smoke alarm has mains power, the battery doesn’t have to be a 10 year lithium battery.
How to Remove a 240V Smoke Alarm Head
In the video, Alex is holding a Brooks branded 240V smoke alarm which has a 9V backup battery. It can be a little bit tricky to get the smoke alarm head away from the base while it’s against the roof, and it’s not easily identifiable how to do this. So we wanted to show how to remove the head easily without damaging the ceiling or using extra unneeded energy.
On the side of the 240V Brooks smoke alarm there is a label with text to insert a flat tool into the slot and depress the tab within the smoke alarm. Once the tool is installed and the tab depressed, simply push the head of the smoke alarm away from your body and the head will come free from the base mounted to the ceiling.
Inside the back of the smoke alarm head you’ll see the 9V backup battery. It is safe to remove this battery and the smoke alarm head is no longer connected to 240V electricity. Simply replace the 9V battery and reinstall the smoke alarm head. Our step-by-step post on how to replace a 240V smoke alarm 9V battery covers this in more detail.
Once the battery has been replaced, position the smoke alarm head against the base by lining up the clips so that they sit nicely against each other. Then slide the head back towards the base so that it is central. Check that the green mains powered light has re-engaged, indicating that the smoke alarm is now re-energised.
It is a good idea to now test the smoke alarm by pushing and holding the test button on the front of the smoke alarm head and listening for the alarm sounding. If your 240V mains powered smoke alarm is chirping intermittently, this may be an indication that the battery is flat and the above procedure needs to be followed.
What Does a Sealed 10 Year Lithium Smoke Alarm Look Like?
Now let’s look at a sealed 10 year lithium battery smoke alarm. This is also a Brooks brand smoke alarm and is a photoelectric type. To remove the battery type smoke alarm from the base, simply turn the head counter clockwise, and it will release.
Inspect the rear side of the smoke alarm head. You will notice that there is no battery visible and that it cannot be replaced without causing damage to the smoke alarm enclosure. If a 10 year lithium sealed battery smoke alarm is chirping, which would indicate a low battery, the smoke alarm must be replaced as it cannot be maintained.
Photoelectric Smoke Alarms and Keeping Them Clean
For any type of smoke alarm to be compliant in the Northern Territory it must be a photoelectric type. Photoelectric smoke alarms are better at detecting slow smouldering fires and are much more sensitive than the previously used ionisation type. Our guide on whether your smoke alarm is the correct type explains how to check the label.
Photoelectric smoke alarms can be quite sensitive, and it is a good idea to regularly clean dust and things such as cobwebs from inside the smoke alarm and around the exterior if present. This can be done quite easily from the ground by using a vacuum cleaner and running it around the outside edges where the grills of the smoke alarm are present. Moisture can also affect smoke alarms and cause false alarms.
In the Northern Territory there are requirements as to the locations that smoke alarms are required to be installed. It is a good idea to check the PFES smoke alarm fact sheets and confirm the smoke alarms in your property are installed in the correct locations and are a compliant type. Read more in our guide to NT smoke alarm regulations.
Frequently Asked Questions
How can I tell if my smoke alarm is battery or 240V?
Look for a solid green light on the alarm head. A solid green light means mains power, so it is a 240V alarm. A battery alarm does not have a solid green light.
Can I replace the battery in a sealed 10 year smoke alarm?
No. A sealed 10 year lithium battery cannot be replaced. If the alarm is chirping to say the battery is low, the whole smoke alarm must be replaced.
Do smoke alarms in the NT have to be photoelectric?
Yes. To be compliant in the Northern Territory, a smoke alarm must be a photoelectric type, which is better at detecting slow smouldering fires than the older ionisation type.
How do I clean a smoke alarm?
Run a vacuum cleaner around the outside edges and grills from the ground to remove dust and cobwebs. Keep moisture away, because it can cause false alarms.
Need Help With Your Smoke Alarms?
If you require any assistance or advice with the smoke alarms at your property, contact us today. See our smoke alarm installation service, request a booking or call (08) 8983 3000.