Smoke alarms are the one piece of safety equipment in a house that everybody owns and almost nobody maintains. They sit on the ceiling doing nothing visible for a decade, and the only feedback most people ever get from them is a chirp at three in the morning.
The part that surprises homeowners is that a smoke alarm has an expiry date, and it is not negotiable. An alarm with a fresh battery and a working test button can still be legally non-compliant and practically unreliable.
The ten year rule
Every smoke alarm is stamped with a date. Depending on the brand it will be the manufacture date, the expiry date, or both, printed on the back or the side of the unit. From the date of manufacture, the alarm has a ten year service life.
That is not a marketing figure. The sensing chamber degrades, dust and insects get in, and the sensitivity drifts. After ten years the manufacturer will no longer vouch for the alarm detecting smoke the way it did when it was new, and Queensland does not accept an expired alarm as compliant regardless of how healthy it seems.
If you have never looked at the date on your alarms, do it this weekend. Take the cover off, read the stamp, and write the replacement year on the unit in marker so the next person does not have to guess.
The five signs it needs replacing now
1. The date stamp is more than ten years old, or missing
Ten years from manufacture and it is done. If there is no readable date at all, the alarm is old enough that the answer is the same.
2. It chirps every thirty to sixty seconds
A regular single chirp is the low battery warning. On a replaceable battery unit, change the battery. On a sealed ten year unit, the chirp usually means the whole alarm has reached end of life, because the battery and the alarm expire together by design.
3. It goes off for no reason
Nuisance alarms that are not caused by cooking or steam usually mean dust, insects or a degraded sensor. Cleaning may fix it once. If it keeps happening, the alarm is telling you it no longer knows the difference between smoke and nothing, which is the failure mode that matters.
4. The test button does nothing, or the alarm is barely audible
Press and hold the test button. You should get a loud, unmistakable alarm. A weak or silent response means replace it, not investigate it.
5. It is an ionisation alarm
Ionisation alarms are no longer compliant in Queensland. They are slower to respond to the smouldering fires that are most likely to start in a home overnight, and they are far more prone to nuisance alarms from cooking, which is why so many of them end up with the battery pulled out. If your alarm is not marked photoelectric, assume it needs replacing. Our summary of Queensland smoke alarm laws sets out the full requirement.
What maintenance actually looks like
Replacement is the big item, but the yearly routine is short.
- Monthly — press the test button on every alarm. On an interconnected system, pressing one should sound all of them, which is also how you confirm the interconnection still works
- Every six months — vacuum the outside of each alarm with a brush attachment to clear dust and cobwebs
- Yearly — replace the battery in any alarm that takes a replaceable one, and re-read the date stamps
- Ten years — replace the alarm itself, whatever condition it appears to be in
If you own a rental, the obligation is firmer: alarms must be tested and cleaned within thirty days before the start of each tenancy, and the records matter when something goes wrong. We handle this for property managers across the Sunshine Coast and Brisbane and supply documentation per property.
Replacing one alarm, or all of them?
Nearly always all of them. Alarms installed at the same time expire at the same time, so replacing one this year and the rest over the next three means paying for four visits and tracking four different dates. It also means mixing old and new units in an interconnected system, and mismatched brands do not reliably talk to each other.
The other reason to do them together is that most houses needing replacement also need more alarms than they currently have. A house built before the current rules will typically have one alarm in the hallway, where compliance now asks for one in every bedroom, in the hallways connecting them, and on every storey.
Hardwired or sealed battery?
Both are compliant. Hardwired alarms with battery backup are the better long term option where there is ceiling access, and they interconnect by cable rather than radio. Sealed ten year battery alarms with wireless interconnection are the practical choice in an existing home where running cable would mean opening ceilings. If we are already in your roof space for other work — a switchboard upgrade, a rewire or a lighting change — hardwiring the alarms at the same time costs very little extra.
What we do
We check what you have, read every date stamp, tell you plainly which alarms are expired and how many the house is short, then supply, install, interconnect and test the lot. You get the alarms placed where the legislation asks for them, not just replaced where the old ones happened to be, and documentation on completion.
See our smoke alarm installation service for what is included. If you are checking compliance items generally, the other one most older homes are missing is RCD protection — our comparison of safety switches and circuit breakers explains why, and both are usually sorted in the same visit.
Not sure how old your alarms are?
We will read every date stamp, tell you which alarms are expired and how many the house is short, then supply, install, interconnect and test the lot with documentation on completion.
Written by Scott Gross, licensed electrician and founder of PMU Electrical, servicing the Sunshine Coast and Brisbane. Licence 146529.