Photoelectric or ionisation?
| Photoelectric | Ionisation | |
|---|---|---|
| What it senses best | Visible smoke, including the larger particles from smouldering fires | Extremely small particles, usually from fast flaming fires |
| The tell-tale sign | No radiation symbol | A radiation symbol on the alarm |
| Radioactive material | None | A small amount, not enough to harm people or the environment |
| Where the rules want it | Required in Queensland and the Northern Territory | Still allowed in WA if it complies with AS 3786 |
Why fire services prefer them
Queensland's fire service says photoelectric alarms (it also calls them optical alarms) respond quicker to a wider range of home fires, like smouldering fires and the dense smoke from foam-filled furniture or overheated wiring. It also lists fewer cooking nuisance alarms among the advantages.
WA's Department of Fire and Emergency Services recommends mains-powered photoelectric alarms. ACT Fire and Rescue suggests swapping an ionisation alarm for a photoelectric one when it's faulty or nearing its expiry date, which is usually 10 years.
Victoria's CFA and FRV see it a little differently. In their view, how many working alarms you have, where they sit and whether they're linked matter more than the sensor type, and they note that dual sensor alarms, combining both kinds, have been shown to perform more consistently across a range of fires.
Who makes them
Each of these makers sells photoelectric alarms in both mains-powered and battery-only versions: Clipsal (its Fire Tek range), Red, Quell, Brooks, CAVIUS and Legrand. The model pages cover which ones link together and which need an electrician.
What to check before you buy
- Photoelectric on the box, and no radiation symbol on the alarm.
- AS 3786 on the label. The 2014 edition has been superseded, and manufacturers now need to meet AS 3786:2023.
- The power type your home needs: 240-volt if you're replacing hardwired alarms, or a sealed 10-year battery where your state allows it.
- Interconnection, if the alarms need to sound together. The linking lists we've seen are brand-specific, so plan to stay with one maker.
- For someone who is deaf or hard of hearing, an alarm that alerts at least two other ways, such as a vibrating pad or a strobe light.
Fitting one: yours or an electrician's?
You can
- Put up sealed wireless photoelectric alarms, which Victoria's fire services say don't need an electrician.
- Test them monthly by holding the test button until it beeps.
- Replace the whole alarm once it reaches 10 years.
Leave to a licensed electrician
- Swapping a 240-volt ionisation alarm for a photoelectric one.
- Interconnecting 240-volt alarms.
- Any mains alarm whose green power light has gone out.
What we'd choose
When an alarm's due for replacement, we'd go photoelectric every time: several fire services recommend it, and Queensland and the Northern Territory now require it. Keep the power type you've got, so hardwired stays hardwired with a licensed electrician doing the swap, and link the alarms so they all sound together.
Want a specialist to sort it?
Tell us the job and your postcode. We match the licence-checked local electrician who does this kind of work, and they call you. No ring-around, and your number goes to them alone.