How Often Should Smoke Alarms Be Tested and Replaced?

Test every smoke alarm once a month using its test button, replace the battery at least once a year (unless it's a sealed 10-year battery), and replace the whole alarm every 10 years. Smoke alarms that are old, disconnected or have flat batteries give a false sense of security, and the sensors inside degrade with age even if the alarm still beeps when tested.

Monthly: press the test button

Push and hold the test button until the alarm sounds. A loud alarm means the battery and horn are working. If it's quiet, weak or doesn't sound, replace the battery and test again. If it still fails, replace the alarm. For high ceilings, use a broom handle rather than standing on a chair.

If your alarms are interconnected, pressing test on one should set off all of them. If some don't sound, the interconnection may have a fault and should be checked by an electrician. See do my smoke alarms need to be interconnected?

Yearly: batteries and a clean

• Replaceable batteries: change them at least once a year. Many people use the end of daylight saving as a reminder.
• Hardwired alarms still have a backup battery that needs replacing, unless they use a sealed 10-year lithium battery.
• Clean the alarm by gently vacuuming the vents to remove dust and insects, which can cause false alarms or slow detection.

An intermittent chirp usually means a low battery. Replace it promptly rather than removing it.

Every 10 years: replace the alarm

Smoke alarms have a working life of about 10 years. The sensor becomes less sensitive over time, so an old alarm may respond late to real smoke even though the test button still works. Check the date printed on the back or side. If it's more than 10 years old, or you can't find a date, replace it. When replacing, photoelectric alarms are generally recommended for homes.

What the rules say in Victoria

All homes must have working smoke alarms. Homes built since 1 August 1997 generally require hardwired (240V) alarms, and newer homes have additional requirements, such as interconnection. Installing or replacing a hardwired alarm is electrical work that must be done by a licensed electrician. See hardwired vs battery smoke alarms.

Rental properties: rental providers must ensure alarms are correctly installed and working, tested according to the manufacturer's instructions at least every 12 months, and that batteries are replaced as needed. Renters should test alarms, report faults and never remove or disable them. See landlord electrical obligations in Victoria.

Where smoke alarms should go

• in or near every bedroom and in hallways connecting bedrooms
• on every level of the home
• on the ceiling where possible, away from corners and air vents
• not directly in kitchens or bathrooms, where cooking and steam cause false alarms

Fire authorities recommend interconnected photoelectric alarms in every bedroom, hallway and living area for the best protection.

Signs it's time to call an electrician

• alarms are more than 10 years old, or you don't know their age
• hardwired alarms are beeping, showing fault lights or not responding to test
• interconnected alarms don't all sound together
• you're renovating, adding bedrooms or managing a rental
• frequent false alarms that cleaning doesn't fix

VU Electrical installs, tests and replaces hardwired and interconnected smoke alarms across Melbourne, with a Certificate of Electrical Safety for the work. See our fire protection services or request a quote.