Twice a year, NSW changes its clocks. It’s the easiest reminder you’ll ever get to look after your smoke alarms.
The whole job takes about 15 minutes for a typical home. It’s the difference between an alarm that wakes you at 2am and one that stays silent. This checklist covers what to do every month, every 6 months and every 10 years, what NSW law requires, and when it’s time to call a licensed electrician.
Why tie it to daylight saving?
NSW clocks go forward on the first Sunday in October and back on the first Sunday in April. Fire and Rescue NSW and the NSW RFS have pushed “change your clocks, change your smoke alarm battery” for years, because a date you already notice is a date you won’t forget.
The next clock change is Sunday 4 April 2027. Put the checklist below in your calendar for that weekend, and again for the first weekend in October.
How often should you do what?
| Task | How often | Who |
|---|---|---|
| Press the test button | Monthly | You |
| Vacuum dust off the alarm | Every 6 months | You |
| Full check (test, clean, inspect, check the date) | Every 6 months, at the clock change | You or an electrician |
| Replace a 9V or alkaline battery | Every 12 months | You |
| Replace the whole alarm | Within 10 years of manufacture | A licensed electrician for hardwired alarms |
Your 6-monthly smoke alarm checklist
- Test every alarm. Press and hold the test button for at least five seconds until it sounds. A broom handle saves you climbing a ladder. If your alarms are interconnected, every alarm in the house should sound together. If one stays quiet, the link has a fault.
- Vacuum the vents. Use the soft brush attachment around the edges and vents. Fire and Rescue NSW recommends doing this every six months. Dust and insects block smoke from reaching the sensor and are a common cause of false alarms. Never spray cleaner or paint on an alarm.
- Check the battery. Standard 9V or alkaline batteries need replacing every 12 months. Make the April clock change your battery day so it’s one date to remember. Sealed 10-year lithium alarms don’t need a battery change, the whole unit is replaced instead.
- Check the date on the back. Every alarm has a manufacture date printed on the back. If it’s more than 10 years old, or past the date the manufacturer specifies, replace it. Sensors lose sensitivity over time, even when the test button still beeps.
- Look for damage. Cracked casings, yellowing, paint over the vents or a missing green power light on a hardwired alarm all mean the alarm needs attention.
- Check your coverage. You need an alarm on every level of the home, including levels without bedrooms, and in the hallway outside the bedrooms. Renovated, converted a garage or added a bedroom? That space may need its own alarm.
How to change a smoke alarm battery
- Battery-only alarm: twist the alarm off its base, swap the battery, refit it and press the test button.
- Hardwired alarm: these run on 240V power with a backup battery. Open the battery compartment, swap the battery and press test. Don’t unscrew the alarm from its wiring. In NSW that’s work for a licensed electrician.
If an alarm keeps chirping after a fresh battery, it’s usually at the end of its life or has a fault. That’s a good time to book in smoke alarm repair and replacement.
What NSW law says
Every NSW home where people sleep must have working smoke alarms on each level, and they must meet Australian Standard AS 3786. That applies to owners as much as renters.
Rentals carry extra duties for landlords and agents:
- Check that smoke alarms are working every year
- Replace standard batteries every year (lithium batteries per the manufacturer)
- Replace alarms within 10 years of manufacture
- Repair or replace a faulty alarm within 2 business days
- Use a licensed electrician for any hardwired alarm work
We cover the full smoke alarm rules in NSW on our smoke alarm page.
When to call an electrician
Some jobs are fine to do yourself. Others need a licensed electrician:
- A hardwired alarm is faulty, chirping after a new battery or past its 10-year date
- You want interconnected alarms, so every alarm sounds when one does
- You’ve renovated or added a bedroom and need new alarms wired in, which can also be a good time for a switchboard upgrade
- You’re a landlord who needs a yearly compliance check done and documented
- An alarm needs moving, for example it keeps going off near the kitchen
Saints Electrical installs, replaces and tests hardwired and interconnected smoke alarms across St George and the Sutherland Shire. We’ll check every alarm in the home, replace anything past its date and leave you with a system you can trust.
Call Chris on 02 9538 7032 or book a smoke alarm check online.
Frequently asked questions
How often should smoke alarms be tested?
Press the test button once a month. Do a full check, including cleaning and checking the date, every six months when the clocks change.
How long do smoke alarms last?
About 10 years. NSW requires alarms in rental homes to be replaced within 10 years of manufacture, or sooner if the manufacturer says so, and the same rule of thumb makes sense for owner-occupied homes.
Where do I find a smoke alarm’s expiry date?
On the back of the alarm. It usually shows a manufacture date rather than an expiry date, so add 10 years to it.
Do 10-year lithium smoke alarms need a battery change?
No. The battery is sealed in and lasts the life of the alarm. When it reaches 10 years, or starts warning you, the whole alarm is replaced.
Why does my smoke alarm go off when I cook or shower?
Usually it’s too close to the kitchen or bathroom, or dust has built up inside. Vacuum it first. If it keeps happening, an electrician can relocate it or fit a type better suited to that spot.