Home Improvement

How to Open a Smoke Alarm

It may sound like a silly question but surely not everyone has a clue about how to open their smoke alarm, be it because they want to find why it’s been beeping like crazy in the middle of the night or because the battery needs changing.

In this article, we’ll look into the different types of alarms. We’ll also explore the reasons for uncalled-for chirping sounds, coming from your device, when there isn’t an obvious and life-threatening cause for concern. And finally, you’ll learn how to open your smoke detector if needs be.

Table of Contents:

First things first. Let’s summarise the purpose of smoke alarms.

What is a smoke alarm?

Smoke alarms detect smoke and can be life-saving devices if fitted correctly in the right places around your home. They are most commonly installed on the ceiling and are triggered by smoke particles in the air. Once the device detects smoke, it starts beeping loudly to alarm you in case of fire. Sometimes, to one’s annoyance, the detector is set off by a harmless whiff of smoke, produced by the kettle or your burnt toast.

Well, there are various types of alarms – each of them, coming with their own specific properties and characteristics.

Smoke alarm types

When considering what sort of smoke alarm to purchase, you should know there are two main types of detectors – ionisation and photoelectric (optical). These two also come in combo versions, known as dual sensor smoke alarms.

  • Ionisation smoke detector. The working principle of these inexpensive alarms is based on a small amount of radioactive material, contained within the device, which detects the tiniest quantity of smoke particles released during fast-flaming fires. This means that if you have an ionisation smoke alarm, you can rely on being warned in good time if the fire is developing fast and without much smoke. The problem, unfortunately, with these devices is that they tend to react to false alarms, such as steam and smoke, emitted from cooking. That is why you shouldn’t fit your ionisation smoke detector directly in or near your kitchen and bathroom.
Ionisation smoke alarms can be battery-operated only or hard-wired to the mains (with a battery backup). Depending on their price tag, you can purchase an alarm that comes with various extra features and interconnectivity properties (cable or wireless that is connected to up to 20 other alarms).
  • Optical/photoelectric smoke detector. The optical smoke detector is set off when smoke enters the device chamber and hits a photocell, inbuilt into the unit. The smoke particles interfere with the light beam, shining away from the cell and the scattered light triggers the detector. The latter is designed to react to slow-burning, smouldering fires, usually fueled by synthetic fabrics, upholstery foam and plastic, and which emit a lot of smoke. The photoelectric smoke alarm can be fitted near your kitchen as it is less likely to be set off by everyday cooking activities.

Optical detectors can be triggered by insects or dust, so you should give the units a good clean now and again.
  • Dual sensor smoke detector. Dual sensor smoke alarms combine both types, mentioned above, and come with their good and nuisance characteristics. On one hand, they will detect both fast-developing and slow, smoky fires just fine and on the other – the device can be easily triggered by your steaming rice cooker because you’ve installed it close to the kitchen.

Other types of alarms

Apart from smoke detectors, you can enhance your safety by installing other types of alarms, which detect different things in a closed environment.

  • Heat alarm. These detect fast an increase in temperature rather than smoke so they won’t be set off accidentally by food burning in your grill or toaster. You can install a heat alarm inside your kitchen. However, if the latter is on the large side, you may need to consider fitting more than one heat detector, as the device is effective only in a small room.
  • CO2 alarm. Faulty gas heating systems and old wood/coal burners cause a number of fatalities in the UK every year. And not because of fire incidents but due to deadly emissions of CO2. That is why a CO2 alarm is a must if your household uses these types of fuel for heating in the winter. As the toxic gas is odourless and invisible, there’s no other way for you to detect if it builds up to a dangerous level.
  • Other combo detectors. The market is also full of different device combinations, such as a smoke and heat alarm or a smoke and CO2 alarm. There are even 3 in one combo detectors, offered by some USA manufacturers, which react to all three elements – smoke, heat and CO2.

Most mid-range single-function or multi-purpose types of alarms are fitted with a test and hush button, as well as a strobe light for people with impaired hearing.
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Why your smoke alarm is beeping or chirping

We’ve already talked about that certain smoke detectors are prone to beep when there is no fire. Steam, coming from your bathtub, smoke that has been generated from cooking or insects accessing the device chamber can all trigger your detector and freak you out all of a sudden.
But there could be also other culprits behind the constant or intermittent chirping sound that your alarm unexpectedly starts producing for no apparent reason. Here’s what they are:

  • Loose battery – if the battery has not been installed correctly, it can trigger a false alarm;
  • Dirty chamber – dusty devices should be regularly cleaned to avoid uncalled-for beeping;
  • Expired battery – battery-operated devices need to be fitted with a new battery once the old one expires;
  • Activated the hush button – the device may chirp at regular intervals if the hush button has been activated;
  • Device interference – wireless alarms may start chirping if there are similar devices close by;
  • Faulty device – naturally, malfunctioning detectors are expected to behave funny and beep;
  • Electrical power issues – hard-wired devices, connected to the mains will be affected in the case of a power cut;
  • Expired device – the alarm reaches its end of life and “makes a loud chirpy announcement” about it.

How to open a smoke alarm

Two main reasons may prompt you to open your smoke detector – to clean it, especially if the device has not been fitted with an insect screen, or to replace the battery. And how you do this will depend on the model you have. You may need to remove the device, first, or just slide away from the battery compartment cover. Use an appropriate tool if the battery cover is secured with a fastener. The instruction manual should provide you with a comprehensive step-by-step guide on how to open your battery-powered smoke alarm. Replace the battery and ensure that it is fitted correctly. Then, test the device to see if it’s functioning as it should.

Remember that hard-wired devices should be switched off from the mains before trying to meddle with them. Watch for the green light indicator on your device and make sure that the detector has been turned off from the main electric supply.

To clean your smoke alarm from dust, use a vacuum cleaner with a soft attachment. If you suspect that an insect has entered the unit, you’ll most probably need to climb up a ladder and detach the device from the ceiling to remove the poor bug. Follow common sense safety procedures to avoid electrical shock injuries or a fall.

Also, consider that mains-powered smoke alarms should be ideally fitted, serviced or replaced by a professional electrician to ensure the guaranteed safety of your family and to stay in line with your home insurance provider’s requirements and conditions.

How to stop your smoke detector from beeping

But let’s go back to the nuisance beeping sound that you may experience one day when forgetting your Sunday roast in the oven and smoke sets the device off. That’s right, your alarm is clean and in perfect order but the chirping doesn’t stop. So, read on and see what else you can do, before attempting to open your smoke detector.

You remember the “hush” button? Its purpose is to silence your device in false alarm situations. It should be located on the detector’s cover. Press it and if the cooking smoke or steam is not too thick, it should hush your device immediately. However, if your roasted chicken has been burnt to death, generating dense whirls of smoke, expect the hush period to last for about 6 to 8 minutes.

Naturally, open the windows to avoid resetting your device automatically after a short while and fill your home again with the dreaded chirping sound.
Note that you can repeat using the ‘hush’ feature as many times as necessary, of course. It’s also good to know that you can silence all interconnected alarms around your house (wireless and hardwired) with the click of one button – that, located on your main smoke detector unit.

When replacing batteries, resetting your device via the ‘test’ button or restoring the electric supply to your mains-connected smoke alarm, a beeping sound is always produced, just the once. This is normal and no other actions are required on your part. Now you know what to do if your smoke detector starts misbehaving even if you and your home are safe and sound.


Do you think this post is informative enough to share with your friends? Or maybe, you’d like to share a funny beeping story or an important safety tip in the comments below?

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