Smoke Alarms - Everything You Need To Know

Smoke Alarm

The smoke alarms in your house are absolutely vital, they save lives. Please before we go any further if you know there maybe an issue with your smoke alarms get it resolved. According to the NFPA (National Fire Protection Association) having a working smoke alarm in your home cuts the risk of you dying in a fire by 60%.

Smoke alarms detect fires by sensing small particles in the air in your home using a couple of different kinds of technologies. Once they detect those particles and the levels go above a certain threshold, they signal the alarm to sound so that you and your family can get to safety and call the fire brigade.

The two common technologies used within some detectors are as follows:

• Ionization Detectors -  They use a small piece of safely shielded radioactive material that ionizes (electrically charges) the air molecules between two metal plates. When smoke is detected it enters the alarm and once the level of particles enters a specific amount the device will register this as a threat, which will set off the alarm. An example of this will be Aico's E141RC.
• Photo Electric - These types are less common but are available. This technology works by detecting light that is reflected off particles from a light beam inside the sensing chamber. When no particles are present in the sensing chamber, the light from the beam does not strike the light detector, indicating all clear. When there are particles present and the amount of light registered by the light detector reaches a certain threshold level, the alarm sounds.  Please see example here!

Both type of technologies are effective and will detect slow burning (smoldering) fires and also fast burning fires. Both technologies have their different strengths too. Ionisation alarms detect small black soot particles from quickly burning fires more easily. This is because the particles are produced more quickly in a fast burning fire. Photo electric alarms are slightly better at detecting smoldering fires due to them picking up the reflective particles in a slow burning fire.

There is a common term used for smoke alarms and that is 'nuisance alarm'. This is when an alarm is so sensitive that it picks up slightly burned toast or your delicious sunday breakfast. People often complain about their alarms being so sensitive but in reality you'd prefer your smoke alarm to be sensitive than unresponsive. 

Due to the nature of the times we are living in and technology always advancing, researches are continuously trying to improve the functions of smoke alarms and I am sure one day in the near distant future we will have smoke alarms that can detect a fire and understand when your bacon is slighlty over cooked... one day!

What to do if smoke alarm is beeping?

Most importantly you need to make sure there is not a fire in your house. If there is, of course evacuate as safely as possible. If there is not a fire the issue maybe that the battery needs to be replaced. Smoke alarms normally 'beep' or 'chirp' every 30 to 60 seconds when the battry is running low. With a "low battery" announcement, disconnect the unit and replace the batteries. You can also put a unit into low battery hush for up to 12 hours on newer units by pressing the test/hush button. 

What can trigger a smoke alarm?

Fire is the most obvious reason but there are other reasons your smoke alarm can trigger.

• Low Batteries or Time to Replace
• Burnt Food
• High Humidity and Steam
• Fireplaces
• Insects

How many smoke alarms do you need in a house?

A stated by the UK governement the minimum requirement is one smoke alarm on each storey of a house, but it is recommended to have them in as many rooms as possible. The safety of yourself and your family is imperative.

How do you change the battery in a hardwired smoke detector UK?

1. Check how your smoke alarm opens so you can get to the battery. Remove the top or slide out the drawer depending on your model.
2. Most smoke detectors are fitted with a 9 volt battery, whether they are mains-powered or battery-powered smoke alarms.
3. Lever the battery out of the drawer, by firmly gripping the base and pulling out. Often it is quite tightly fitted into the drawer so you might need to use some pressure to remove it.
4. The drawer has markings to show where the negative and positive poles of the battery should go. Make sure you align these correctly when you fit the new battery. If your insert the battery into the smoke alarm the wrong way around  it will not work. There is usually a warning in the drawer to make this clear.
5. Insert the new battery in the drawer, making sure you align the negative and positive poles correctly. Only replace the battery with a brand-new one.
6. Make sure the battery is firmly engaged. Close the drawer, if there is one, making sure it is fully closed. Otherwise replace the top.
7. Press the test button on the top of the smoke detector, and the alarm should sound for a few seconds. 

How long do smoke detectors last?

The short answer is 10 years, you should have your smoke alarm changed atleast every 10 years. According to Consumer Reports, most detectors come with a five to seven year warranty. We recommend checking your warranty period before buying your chosen model. We try to include this on every prouct page of Smoke Alarms Shop.

Where should a smoke alarm be placed in a room?

The majority of smoke alarms are installed on the ceiling but some are installed on walls. If they are installed one a wall you must remember they need to be atleast 12 inches away from the ceiling.

Are smoke detectors easy to install?

Smoke alarms are easy to install, they are easier than most electrical items in your home. But they are one of the most important devices so we would recommend an electrician come and install it for you. That way you know the installation is safe and you are safe is a fire was to break out.

Who is eligible for free smoke alarms UK?

For example, some can offer you a free alarm if you’re aged above 75, disabled, or suffer from long-term illness. You can get a free fire alarm installed buy booking a Safe and Well visit.

This service is free and is carried by most fire services in the UK. To find your local fire service, Google your area as well as "fire service". You can book an appointment by using an online form or call your local fire service.