More than one-third (38%) of home fire deaths happen in places without smoke alarms. That’s a scary statistic. But here’s some good news: staying safe is easy.

Smoke and carbon monoxide detectors prevent fires and protect your loved ones. But do you need a combination smoke and carbon monoxide detector, or are separate units better? Let’s break it down so you can make the best choice for your home. 

What Is a Smoke Detector?

A smoke detector senses smoke and warns you about a potential fire. It’s a must-have for home and business safety. There are two main types: photoelectric and ionization.

Photoelectric smoke detectors use light to detect smoke. When smoke enters the chamber, it scatters the light and triggers the alarm. They’re better for detecting smoldering fires, like a couch that slowly burns. They’re also less likely to go off when you burn toast, so they’re great for kitchens.

On the other hand, ionization smoke detectors have a small amount of radioactive material between two electrically charged plates. When smoke enters, it disrupts the flow of ions and sets off the alarm. They respond faster to fast-burning fires, like a flaming curtain.

Experts recommend having both types or a dual-sensor alarm that combines them. Smoke detectors can be hardwired or battery-powered. Residential detectors sound loud alarms, while commercial ones connect to a central fire alarm system.

What Is a Carbon Monoxide Detector?

A carbon monoxide (CO) detector alerts you when there’s too much carbon monoxide in the air. CO is a dangerous gas you can’t see, smell, or taste. It comes from sources like faulty furnaces, gas stoves, car exhaust, and generators. Even low levels of CO exposure over time can make you sick, while high levels can be deadly.

CO detectors work by sensing the amount of carbon monoxide in the air and triggering an alarm before it reaches dangerous levels. There are three main types of sensors. Biomimetic sensors use a gel that changes color when exposed to CO. On the other hand, metal oxide semiconductors detect changes in electrical resistance when the gas is present. Meanwhile, electrochemical sensors measure changes in electrical currents caused by CO exposure. No matter which type, all carbon monoxide detectors serve the same purpose: warning you in time to prevent poisoning.

Can You Have a Carbon Monoxide and Smoke Detector in One?

Yes, you can have a carbon monoxide and smoke detector in one. Combination carbon monoxide and smoke detectors provide two types of protection in one unit. They detect smoke from fires and dangerous levels of CO.

Most combo detectors use ionization or photoelectric sensors for smoke and electrochemical sensors for CO. Some models even have voice alerts that tell you whether smoke or CO triggers the alarm. This can save lives in an emergency when quick action is needed.

Some combo detectors also have useful features like test buttons, indicator lights, and LCD screens that display CO levels. If you go with a combo unit, make sure it meets safety standards and has proper certifications. 

Don’t forget regular maintenance, too. Test it monthly and replace the batteries as needed. Remember, a working detector can make all the difference in keeping your home and family safe. 

Should You Get a Combination Smoke and Carbon Monoxide Detector?

Yes, you should get a combination smoke and carbon monoxide detector unless you already have separate smoke and carbon monoxide detectors. 

A combination smoke and carbon monoxide (CO) detector is a great option for home safety. Instead of buying separate alarms, you get two types of protection in one device. Fires and CO leaks are serious dangers, and a combo alarm covers both. 

Smoke detectors won’t detect CO, and CO detectors won’t detect smoke. Since CO is an odorless, invisible gas, it can build up without warning, making a detector essential. On the other hand, fires spread quickly, and early smoke detection can save lives. A combination alarm simplifies things by monitoring for both threats at once.

While separate smoke and CO detectors work fine, a combination unit offers convenience, saves space, and offers complete protection. A combo detector is worth considering if you want an easy, reliable way to keep your home safe.

How Long Does a Smoke and Carbon Monoxide Detector Last?

A combination smoke and carbon monoxide detector usually lasts seven to ten years, depending on the model. Smoke alarms usually have a lifespan of about ten years, while CO detectors tend to last five to seven years. Since a combo unit includes both, most manufacturers recommend replacing it every seven to ten years to make sure it works.

Even if your detector seems fine, its sensors weaken over time, making it less reliable. Some models will chirp or display an alert when it’s time for a replacement. 

If your detector has replaceable batteries, swap them out at least once a year. If it has a sealed lithium battery, the whole unit needs to be replaced when the battery dies. Closely follow manufacturer guidelines for the best protection as well. 

How Does a Smoke and Carbon Monoxide Detector Work?

A combination smoke and carbon monoxide detector works using two separate sensors housed in one device. The smoke sensor, usually photoelectric, detects fire by sensing changes in light patterns caused by smoke. When smoke enters the chamber, it scatters light and triggers the alarm. 

The carbon monoxide sensor, usually electrochemical, detects CO using electrodes immersed in a chemical solution. When carbon monoxide is present, it reacts with the electrodes and creates an electrical current. The alarm is activated once CO levels reach a dangerous threshold. 

A combo unit's big advantage is that it saves space and reduces the number of devices needed. It sounds an alarm when either sensor detects a problem. Many models have distinct alerts or voice notifications to differentiate between smoke and CO threats. 

Some also include digital displays to show CO levels. These devices can be battery-powered, hardwired, or smart-enabled, with features like app alerts for remote monitoring. Combination carbon monoxide and smoke detectors are also installed like regular smoke alarms. 

Where to Place Combination Smoke and Carbon Monoxide Detectors

Putting your combination smoke and carbon monoxide detectors at the right spots makes a huge difference. Here’s where to place them:

Bedrooms

Install a detector inside every bedroom. Fires can start while you sleep, and smoke alarms inside bedrooms give you an early warning. Since carbon monoxide (CO) is colorless and odorless, having a detector in each bedroom makes sure anyone can hear the alarm and wake up in time to escape.

Kitchen

Most home fires start in the kitchen, so having a detector nearby is a must. Place it at least 10 feet away from the stove and oven to avoid false alarms. If your kitchen is small, install the detector just outside the kitchen area.

Every Floor of Your Home

Install at least one combination detector on each level, including basements and attics. Fires and CO leaks can happen anywhere. Having alarms on every floor increases the chance of early detection.

Living Areas

Place a detector in common areas like living rooms and family rooms, especially if they contain fire hazards like candles, space heaters, and curtains. 

Staircases

Put a detector near stairways, especially those leading to upper floors, basements, or attics. Smoke rises, so placing an alarm at the top of a staircase helps detect it before the fire spreads to other parts of the home.

Near Attached Garages 

Do you have an attached garage? If yes, install a detector near the door connecting it to your home. Vehicles, gas-powered tools, and generators produce carbon monoxide, which can seep into your house. We also recommended installing at least one combo detector if you have a detached garage. 

Near Fuel-Burning Appliances

Install a detector within 10 feet of furnaces, water heaters, and fireplaces. These appliances can produce carbon monoxide if they malfunction. However, avoid placing the detector too close to avoid false alarms.

Do you need a more detailed guide? Check out where to place carbon monoxide detectors and smoke alarms here. 

Why Is My Smoke and Carbon Monoxide Detector Chirping?

Ignoring a chirping alarm isn’t worth the risk. Figure out what’s causing it and fix the issue to keep your home safe. Here are the top reasons why your smoke and carbon monoxide detector chirps:

1. Smoke or Carbon Monoxide

A continuous alarm means smoke or dangerous CO levels in your home. Smoke alarms usually beep three times a row, while CO alarms beep four times. If you hear this, get out immediately and call emergency services. 

2. Low Battery 

A single chirp every few minutes usually means the battery needs to be replaced. Swap it out immediately, or your alarm won’t work when needed. If your detector is hardwired, its backup battery might be running low.

3. It’s Expired

Smoke and CO detectors don’t last forever. Most should be replaced every seven to 10 years. Check the manufacturing date if your alarm keeps beeping even with a new battery. 

4. Malfunction

Smoke and CO detectors sometimes beep because of an internal issue. Press the reset button or check the manual for troubleshooting steps. If it keeps chirping, it might be time for a replacement.

5. Power Issues

A hardwired detector might chirp after a power surge or outage. Check if the circuit breaker tripped and reset the detector if needed. If the problem persists, call a technician to inspect it. 

How to Install a 10-Year Smoke and Carbon Monoxide Detector

Installing a combination smoke and carbon monoxide detector doesn’t have to be hard. Here’s how to do it: 

1. Pick the Right Spot

Install detectors on each floor, inside and outside bedrooms, and near stairways. Keep them at least 10 feet from stoves and furnaces to prevent false alarms. 

2. Mark the Holes

Use the mounting bracket as a template. Hold it against the wall or ceiling and mark where the screws will go.

3. Drill and Insert Anchors

Drill holes where you marked them using the drill bit size recommended in your manual. Then, insert the wall anchors. Tap them in gently with a hammer if needed.

4. Attach the Bracket

Line up the bracket with the anchors and secure it using the screws provided.

5. Install and Activate the Alarm

Does your detector have a built-in battery? If yes, activate it using the switch. If it has replaceable batteries, insert them correctly. The power light may flash or beep when it’s on.

6. Test the Alarm

Press and hold the test button to make sure it works. If it doesn’t, check the manual for troubleshooting, call an electrician, or replace the unit.

Will My Smoke Detector Go Off if There Is Carbon Monoxide?

No, a regular smoke detector won’t go off if there’s carbon monoxide in the air. Smoke detectors only detect smoke from fires, not CO, which is odorless and invisible. That’s why you need a separate carbon monoxide detector to stay safe. Fires can sometimes release CO, but a smoke alarm won’t always catch it. 

On the other hand, CO leaks can happen without smoke or flames, making a smoke detector useless for that threat. Having both types of alarms gives you full protection. Whether all alarms go off together depends on your system. Some are interconnected, so if one detects danger, they all sound. Others, like battery-operated models, work independently, so only the triggered alarm will go off. If you’re unsure, check your manual or test your system.

Do I Need a Carbon Monoxide Detector if My House Is All Electric?

You need a carbon monoxide detector even if your house is all electric. While electric appliances don’t produce CO, the gas can enter your home from outside sources. If you have an attached garage, running a car inside can release CO into your home. A backup generator placed too close to your house during a power outage can also be a risk. Plus, local building codes may require CO detectors. It’s a small investment for added safety.

What Smoke Detector Do Firemen Recommend?

The US Fire Administration recommends having ionization and photoelectric smoke alarms or dual-sensor smoke alarms that contain both. Ionization detectors respond faster to flaming fires, while photoelectric alarms detect slow, smoldering fires better. 

Since no one can predict what type of fire might occur, having both types ensures better protection. They also recommend interconnected alarms so that when one sounds, all do. 

Do I Need a Carbon Monoxide Detector if I Have No Gas?

You still need a carbon monoxide detector even if you don’t have gas appliances. Carbon monoxide can come from other sources, like an attached garage, a running car, or a running generator too close to your home. It’s an odorless, colorless gas that can be dangerous if it builds up indoors. Fires can also produce carbon monoxide, so having a detector adds an extra layer of safety. 

Does Carbon Monoxide Rise or Sink?

Carbon monoxide doesn’t rise or sink. It mixes evenly with the air. It’s slightly lighter than air but not enough to rise or sink. Instead, it spreads throughout a room. It might start near the ceiling if it comes from a heat source, but it won’t stay there.  

As the air cools, CO levels out and blends in. That’s why CO detectors should be placed at breathing height, where you'll most likely inhale the gas. 

What Are Two Warning Signs of Carbon Monoxide Poisoning?

Two major warning signs of carbon monoxide poisoning are headaches and dizziness. You might also feel weak, nauseous, or confused if exposed to too much CO. 

Since CO is odorless and invisible, you might not realize what’s happening until it’s too late. It can be especially dangerous while sleeping because you won’t notice the symptoms. If you feel sick in an enclosed space and suspect CO poisoning, get fresh air immediately and call for help. 

How to Tell if Carbon Monoxide Is in the Air?

You can't see, smell, or taste carbon monoxide, so the only reliable way to know if it's in the air is with a carbon monoxide detector. CO poisoning symptoms can be a clue, but you might be in danger by the time you feel them. Stay safe by installing CO detectors near bedrooms and common areas. If the alarm goes off, get outside immediately and call for help. Don’t take chances. Remember, carbon monoxide poisoning is deadly but preventable.

Why Do Smoke Alarms Randomly Go Off at Night?

Smoke alarms go off randomly at night for different reasons. A low battery is one of the most common causes. Dust, humidity, and steam can also mess with the sensors, as can smoke from cooking or a fireplace. 

Plus, insects inside the unit and sudden temperature changes might set it off. If your alarm is old (over 10 years), its sensors might not work properly. Regular maintenance helps prevent false alarms so you can sleep peacefully.

What if the Carbon Monoxide Alarm Goes Off But No Fire?

If your carbon monoxide alarm goes off but there’s no fire, don’t ignore it. First, get everyone outside and into fresh air. Call 911 and let the professionals check for carbon monoxide. 

Even if you smell nothing, carbon monoxide is invisible and odorless, so it’s better to be safe. If it’s a false alarm, check if the detector needs new batteries or is placed near something that could trigger it, like a furnace or garage. Regularly testing and replacing your alarm ensures it works when needed. 

Conclusion

A combination smoke and carbon monoxide detector is a smart, space-saving way to keep your home safe. Fires and carbon monoxide leaks are real dangers, and having the right detectors can save lives. Whether you choose a combo unit or separate detectors, regular maintenance and proper placement are key. 

Smoke and carbon monoxide detectors are essential, but they’re just one part of home safety. Pair them with fire sprays, fire blankets, and flame shields for extra protection.

Do you want reliable, easy-to-use, and affordable tools to put out small fires before they spread? Check out Prepared Hero’s fire prevention tools here, and get up to 51% off on certain items. Stay safe, hero!