Do Smoke Detectors Go Bad

How often have you heard a news report which stated “There were no working smoke detectors” following a house fire where lives were lost? 

So sad, but also avoidable! 

Even if your smoke detectors are cheap and pretty basic, they can definitely be life savers. 

Smoke detectors are not all alike. Some work better than others and many options are available today to make them safer and easier to use. 

However, there might be some things you don’t know about smoke detectors that may make you rethink the ones you have now. 


The fact is that all smoke detectors need to be replaced when they reach 10 years of age, and in many instances, smoke detectors can fail or become problematic well before this time. 

Nonetheless, there is much more compelling information I’d like to share with you. 

You can never be too well informed when it comes down to the safety of you and your family.

If You'd Prefer To Watch A Video

If you would prefer to digest this information by watching a video, click 'play' below. Otherwise, keep reading below...

Smoke Detectors
Don't Last Forever

Were you aware that most smoke alarms self test for smoke every 40-60 seconds as it constantly monitors the air 24 hours a day! This means that during the 10-year lifespan of an alarm, the electronics in a smoke detector have carried out over a staggering 7,884,000 tests!

The number of times a smoke detector tests for smoke over its 10 year lifespan

After so much use, components may become less reliable. 

This means that as the alarm gets older, the potential for failure increases, as the sensitivity, and therefore the effectiveness of the smoke detector continues to reduce over time. 

This is the reason why it is recommended you replace your smoke detector every 10 years for optimum performance and safety. 

Smoke detectors are subjected to 10 years worth of dust, insects and debris accumulating in the device, not to mention possibly being neglected with lack of maintenance over this period. A buildup of dust and particle matter can also affect the performance of the smoke detector. 

The Signs Which Indicate Your Smoke Detector May Be Failing (or Has Failed!)

Here’s How to Check Your Smoke Detector Today!

Firstly, check the expiry date to see if it is still serviceable. As discussed above, all smoke alarms have an operative service life of 10 years, after which they need to be replaced.

This date will usually be written on a sticker on the side or on the back of the alarm.

Check Expiry Date Of Smoke Alarms

Most smoke detectors will have a date code on the back of the device. Usually, this is the manufacturing date, so simply add 10 years to this date. If the detector is older than 10 years, it needs to be replaced

#1: Vacuum the alarm on the outside, and also around any openings. This is to clean the inside of any dust, debris, cobwebs and insects.

Cleaning A Smoke Detector With A Vacuum

A vacuum cleaner is great for cleaning a smoke detector. It will get into any nooks and crannies and clean the alarm of any debris or insects. Detach the body of the smoke detector from its base and vacuum on the reverse side for a thorough clean. Concentrate on cleaning around any openings you see on the front, sides and rear of the detector

Alternatively, use an aerosol air blaster or a small electric blower.

#2: Insert a new battery (if it’s a smoke detector model with a removable 9-volt battery).

#3: Clean the outside of the alarm with a damp cloth and general purpose cleaner.

#4: Apply a small amount of insect surface spray to another cloth then gently wipe over the face of the alarm and around the surrounding ceiling. This tip will limit the chance of insect ingress.

Applying Insect Spray To Smoke Detector

Apply some insect surface spray (not the knockdown spray, but the surface spray) to a cloth and lightly apply it to the face of the smoke detector and on the ceiling to help prevent insect ingress in the detector

Press the test button on the alarm to ensure it works.

Press The Test Button On Your Smoke Detector

All smoke detectors will have a test button on them (oftentimes, it's the same button as the 'hush' button) and it should be clearly labelled on the face of the detector. Press and hold this button for a second or two and the detector should sound

Install a new 9-volt battery if your alarm has one (if it's a mains powered smoke alarm, it will still have a back up battery of some sort and most of them are 9-volt batteries).

So, if you’ve checked everything and you’re confident your smoke detectors are still in date, plus you’ve serviced the alarms as well, I bet you’re feeling really good knowing that you can rely on your alarms doing their job if the worst should happen. 

Many Smoke Detectors Fail Earlier Than 10 Years

This is a fact, so don’t fall into the trap of thinking a smoke detector is made to last for 10 years, so therefore it will. 

While undertaking the services we carry out on smoke detectors daily in Queensland, Australia, we see a high number of faulty smoke alarms each week, most of them having failed in well under 10 years! 

Remember, smoke alarms can only save lives if they are well maintained and work properly, so the message here is that you remember your monthly smoke detector maintenance which should alert you to any potential issues.

Help! My Smoke Detector Keeps Chirping!

If your smoke detector is chirping or behaving erratically, it often doesn’t necessarily mean the alarm is faulty or going bad. 

Quite frequently, there is a simple explanation, and it’s fixable:

But importantly of course, as we discussed earlier, check the expiry date of your smoke alarms while looking at them, and if anything is 10 years or older, simply organise to have them replaced.

Smoke Detector Technology is Evolving

Please don’t be the type of person who expects their household smoke detectors are going to last as long as the house itself. 

They don’t, and are not meant to. 

The great thing is that smoke detector technology is evolving, and if you upgrade your smoke detectors now, you’ll likely acquire a state of the art device with advanced in-built features to let you know quicker in the event of a fire, PLUS a swathe of internal improvements to limit the chances of false alarms.

Brooks Smoke Alarm Dust Compensation Algorithm

These new smoke alarms from Brooks Australia feature advanced dust compensation algorithms. In other words, they can tell the difference between dust and real smoke to limit the chance of false alarms

You’ll be pleased to hear that modern smoke detectors are far more reliable than those of old, and many of the shortcomings of those former ones are now a thing of the past.

If You Have Any Doubts...

If you have ANY reason to believe your smoke detectors are going bad, don’t hesitate to replace them immediately.

A working smoke alarm is critical for the early detection of a fire in your home, giving you and your family time to escape. 

A working smoke alarm stands guard around the clock!  

The majority of fatal fires happen when families are asleep because occupants are unaware of the fire until there is not adequate time to escape. 

Smoke and deadly gases tend to spread farther and faster than heat. 

That is one reason why most fire victims die from inhalation of smoke and toxic gases, not from burns. 

It can take as little as three minutes for a fire to take hold, and it takes just two quick breaths of thick, black smoke to render a person unconscious! 

These are very frightening facts! 

Do you really want to risk your life with a device that you have some niggling doubts about?

The safety of you and your family is far too important to risk on the chance that your old smoke detector might still work when you need it the most!

And Now I'd Like To Hear From You...

There is a quite powerful message about fire safety I wanted to share with you in this article. 

There may be things you’ve read here that you were previously unsure of, and hopefully the article has increased your awareness of the importance of working smoke detectors. 

I’d love to hear your thoughts in the Comments box below. 

Please feel free to ask any questions you may not be sure of, but I’d also enjoy hearing what you liked about the article. 

It’s over to you now …

Luke Pritchard
Luke Pritchard

Luke is an electrician of 19 years and founder of 'Smoke Alarmed' - a smoke alarm installation, service and testing company on the Sunshine Coast, QLD Australia. Husband and father to two ‘hyperactive’ boys, and one little girl just as 'rough and tumble' - if he looks a little bruised and sleep-deprived, that’s probably why ;) 9th worst surfer on the Sunshine Coast.

    4 replies to "Do Smoke Detectors Go Bad?"

    • Sandra Duke

      Does it take a electrician to replace electric smoke alarm?

    • Fred

      Excellent post!

    • KimmyC

      Thank you so much for this post. It seems that I have a failing smoke detector and all of the detectors in the house are well beyond ten years old! I would call you but it’s a bit of a trip to the USA. But seriously, I am so appreciative of this article. I had no idea!

    • Gail Bates

      Dear Luke
      Thank you for the very informative video on your website, we now know our smoke alarms are ready to be replaced and will do so today.
      Could you please recommend a good alarm for Us to purchase. We live in Newcastle so cannot access your service.

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