Why is my smoke alarm beeping, and does it need replacing?
A single beep every minute or so usually means the battery is going flat, so put in a new one. If it still beeps, or the alarm is more than 10 years old, replace the whole alarm. You can change a battery yourself. Anything to do with the wiring of a hardwired alarm is a job for a licensed electrician.
If it's the full alarm rather than a chirp, treat it as a fire until you know otherwise. If there's smoke, or you aren't sure, get out and call 000.
What makes a smoke alarm beep?
- A battery going flat. CFA and Fire Rescue Victoria say a beep once every 60 seconds or so could mean this. The NSW Government says alarms should give a warning sound when the battery needs replacing.
- Dust or insects. Fire and Rescue NSW says dust, insects, humidity and age can all affect an alarm.
- Age. Fire and Rescue NSW says sensitivity falls over time, so all types should be replaced at least every 10 years.
- A fault. CFA and Fire Rescue Victoria say to replace the entire alarm if it still beeps after a new battery goes in.
How do you stop it beeping?
- Find the one that's beeping. Listen at each alarm. Use a sturdy ladder, and get someone to hold it.
- Check its age. Fire and Rescue NSW says the date or batch number is usually on the base, near the battery compartment. A number like 2406 may mean the 24th week of 2006, and some alarms now show an expiry date. If it's over 10 years old, replace it.
- Change the battery, if it has a removable one. Inbuilt 10-year lithium batteries can't be replaced, so the whole alarm has to go.
- Vacuum it. Fire and Rescue NSW says to do this every six months anyway. It helps stop false alarms, and lets smoke reach the sensor.
- Test it. Press and hold the test button for at least five seconds, until you hear the beeps.
- Still beeping? Replace the alarm. If it's hardwired, call a licensed electrician.
A new alarm can mean new screw holes. If your home was built or renovated before 1990, don't drill the ceiling until you know what it's made of, because it may contain asbestos.
Don't leave it with the battery out. CFA and Fire Rescue Victoria call that a primary reason alarms don't work when they're needed. The NSW regulation also makes it an offence to remove or interfere with a smoke alarm in a building where people sleep, unless you're repairing, maintaining or replacing it.
Can't get up there? Fire and Rescue NSW says it can assist older people, or those physically unable to change a battery, through its Home Safety Visits.
What if the alarm is hardwired?
A hardwired alarm runs on 240 volts from your home's wiring, with a backup battery in case the power goes out. So it can still beep for a low battery, and if it has a battery door, you can change that like any other. If the alarm has to twist off its base to reach the battery, follow the maker's instructions. If it keeps beeping, or it's over 10 years old, it needs replacing, and that's a job for a licensed professional. Don't disconnect it from the wiring yourself.
Do smoke alarms have to be hardwired in NSW?
Not as a general rule in an existing home, though an approval or fire safety order can require it. The NSW regulation requires working alarms on every storey, on or near the ceiling, in the hallways near bedrooms, and they must meet Australian Standard AS 3786. It only requires mains power or a sealed 10-year battery for shared accommodation like boarding houses, hostels and nursing homes. For a private home, the NSW Government's note from when the law began says hardwired or battery is the owner's choice.
That's the legal minimum. Fire and Rescue NSW recommends hardwired and interconnected alarms wherever possible, or 10-year lithium alarms if they can't be hardwired. It recommends interconnected alarms in every bedroom, living space, hallway and stairway, and even the garage. Interconnected means that if one senses smoke, they all sound.
New homes are different. The National Construction Code requires mains power and interconnection, and building work on an existing home can bring in its own requirements, so ask your builder or certifier if you're renovating.
What about 1 January 2027? You may read that homes must have interconnected alarms by then. That's Queensland's deadline. We couldn't find it in the NSW regulation, or on the Fire and Rescue NSW or NSW Fair Trading pages, as at 7 November 2026.
What if you're a landlord or a tenant?
NSW Fair Trading sets out more for rentals. Landlords can't pass this responsibility to tenants through the agreement, and they must:
- Keep at least one working alarm on each storey, and check every alarm each year.
- Replace removable batteries yearly, or lithium batteries when the maker says.
- Replace alarms within 10 years of manufacture, or sooner if the maker says.
- Repair or replace a faulty alarm within two business days of finding out.
- Use a licensed electrician for hardwired alarms.
Tenants should tell the landlord or agent as soon as an alarm isn't working, even if it's only a flat battery. A tenant can change a removable battery after giving notice, and must tell the landlord within 24 hours afterwards. If a hardwired alarm isn't fixed within two business days, the tenant can arrange a licensed electrician and seek the cost back. Neither applies to social housing. Different rules can apply in strata, where the owners corporation looks after the alarms.
Alarms past 10 years, or hardwired ones to replace? Book a time for us to look. We fit, test and replace them, and you get the quote in writing. We work across the Northern Beaches, the North Shore, the Eastern Suburbs and the Inner West.
Prefer to talk now? Call 0466 805 580.
Common questions
How often should smoke alarms be replaced?
At least every 10 years, or earlier if the maker says so. That's the Fire and Rescue NSW advice for all types.
Do I need an electrician to change a battery?
No. A removable battery is yours to change. You'd only need a licensed electrician to replace or repair a hardwired alarm.
It goes off every time I cook or shower. What do I do?
Don't take the battery out. Fire and Rescue NSW says a common mistake is putting alarms too close to the kitchen or bathroom, so it may need moving. CFA and Fire Rescue Victoria also suggest considering a photoelectric alarm in place of an ionisation one. Moving a hardwired alarm is a job for a licensed electrician.
Where do I put the old alarm?
Fire and Rescue NSW says you can drop old alarms off for free at a Household Chemical CleanOut event or a Community Recycling Centre.
Do you do other electrical work?
Yes. Switchboards, safety switches, lighting, power points, rewiring and fans. See our Electrical page.
Where this comes from
Sources checked on 7 November 2026.
- CFA and Fire Rescue Victoria, Smoke alarm brochure
- NSW Department of Planning, Smoke alarms advisory note (March 2006)
- Fire and Rescue NSW, Smoke alarm questions and answers
- Fire and Rescue NSW, Smoke alarm maintenance guide
- Fire and Rescue NSW, Smoke alarm buyers guide
- Fire and Rescue NSW, Smoke alarms: what is the law?
- NSW legislation, Environmental Planning and Assessment (Development Certification and Fire Safety) Regulation 2021, Part 13
- National Construction Code 2022, Housing Provisions, Part 9.5 Smoke alarms and evacuation lighting
- Queensland Fire Department, Smoke alarms
- NSW Fair Trading, Smoke alarms in a rental property
- NSW Government, Asbestos (NSW Planning)
