Stop! Ensure the Correct Placement of Your Carbon Monoxide (CO) Detector

Do you have a carbon monoxide detector, aka a CO detector, installed at home? If you do, congratulations, you just made your home a lot safer. If you don’t, well, what are you waiting for?

Having a CO detector at home is something many homeowners fail to do. They think it’s an unnecessary expense, believing that they will never need it.

This is also likely the mindset of the roughly 72,000 people who got poisoned by carbon monoxide between 2006 to 2010. Or the more than 400 people, on average, who experience carbon monoxide-related deaths every year. Sadly, many people still fall victim to it every year.

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If you don’t want you and your household to be part of those statistics, you should get them installed. More importantly, make sure that the location of each of your CO detectors is the best place for one to be found.

And unless you live in a small studio unit, you really should mount more than one CO detector in your home.

CO detector

Carbon Monoxide Detector Placement: Where to Install CO Alarms at Home

It’s not enough that there are CO detectors in your home. The location of these detectors also matters a lot – each one needs to be mounted at the best place possible and at an ideal height. Whether you place it high or low on the wall or on the ceiling itself will affect its performance.

The general gist of it is that you need to mount these detectors in areas in your home that are a few feet away from appliances and equipment that use up fuel or any combustion source, as well as in rooms you spend the most time in.

Take note, they should be some feet away from these combustion sources, not within their direct proximity.

To understand why placement is important, you need to understand the basics of CO detectors, including how they work, why this gas is dangerous and should be taken seriously, and the warning signs if you or anyone in your household is experiencing carbon monoxide poisoning.

We’ll delve deeper into all of these throughout this article.

Sources of Carbon Monoxide

The bad news is, carbon monoxide can be easily released in your home by any source that is unable to completely burn fuel. The good news is, they are usually at safe levels. It’s only when they are in excessive amounts when they cause damage.

In a report by the Centers for Disease Control and Prevention, or CDC, they found out that these six are responsible for claiming the most victims of carbon monoxide poisoning:

  1. Gas space or portable indoor heaters without adequate ventilation
  2. Blocked chimney or furnace, as well as those with leaks
  3. Fuel-fired equipment that experience back drafting
  4. Stoves powered by gas
  5. Appliances and equipment that run on gasoline, such as generators
  6. Exhaust coming from vehicles, especially if the garage is attached to your home

Do note that there are also other common sources of this gas, such as:

  • Barbecue grills
  • Fireplace
  • Gas-powered dryer for clothes
  • Water heater
  • Boiler
  • Smoke from tobacco
  • Wood stoves
  • From your neighbors who use fuel sources, especially if you live in the same building

Basically, anything that uses and burns fuel, wood, natural oil or gas, propane, or coal will produce carbon monoxide. At small amounts, it can still be considered safe; after all, carbon monoxide is present everywhere. The problem lies if the gas is constantly being released and there is nowhere for it to go. This is why having proper ventilation in any location where combustion sources are found is crucial.

Carbon Monoxide Poisoning Symptoms to Look Out For

Because it is an invisible gas, anyone who gets affected by it may not easily understand that what they are experiencing is carbon monoxide poisoning – they might think that they just caught the flu or a bug from somewhere.

At the early stages, anyone who gets carbon monoxide poisoning will normally get these symptoms, which are akin to the typical flu:

  • Headaches
  • Nausea
  • Dizziness
  • Difficulty breathing or shortness of breath
  • Stomach pains

What makes it different is that those affected will not have elevated temperatures, unlike those suffering from the flu. And if exposure to the gas continues for hours, those affected will eventually experience these more serious symptoms:

  • Confusion and memory issues
  • Feeling of intoxication
  • Vertigo and other motor problems
  • Blurred vision
  • Fainting and loss of consciousness
  • Chest pains and rapid heartbeats
  • Weakness
  • Seizures
  • Respiratory problems

If a number of these symptoms are present, you need to get those affected by the gas to leave the house first to get fresh air outside. Don’t forget to call the emergency paramedics, as exposure to it may require medical intervention, such as oxygen therapy.

With severe and prolonged contact, anyone who experiences carbon monoxide poisoning are also at risk of developing the following health issues:

  • Miscarriage or fetal death for pregnant women
  • Heart ailments
  • Brain injuries

And worst of all, carbon monoxide poisoning can cause death.

Those who are awake may quickly determine if they are feeling sick. Unfortunately, this cannot be said for those who get poisoned while asleep. This is why most fatalities of carbon monoxide poisoning are caught unaware while they sleep.

Avoiding these situations is possible with CO detectors, that’s why it is a vital device in any home.

How Do Carbon Monoxide Detectors Work?

Carbon monoxide is infamously known as an “invisible or silent killer”, and this is what makes some people skeptical about getting CO detectors for their homes. Smoke and fires are visible, so you can confirm whether or not their respective alarms are working or not. You can’t say the same for a CO detector.

We know that carbon monoxide is a type of gas that is not only invisible but also doesn’t smell, nor has a certain taste and can’t be heard. Because of these characteristics, it is impossible for us to detect it with just our senses. This is why it is responsible for hundreds of deaths each year.

If we ourselves can’t discover the presence of carbon monoxide in our homes, then how do the CO detectors do it?

To know how they work, we must first understand that there are three different types of CO sensors available in the market:

  • Biomimetic – usually a strip that you can stick on surfaces, it consists of a gel cell or chem-optical that will darken in color when it detects the presence of carbon monoxide, just like how hemoglobin in our blood turns into a darker color when in contact with carbon monoxide. And once that gel changes its color, the CO detector will trip.
  • Metal Oxide Semiconductor – has a silica chip installed that come with circuits capable of detecting carbon monoxide. When these circuits come into contact with the gas, the electrical resistance of the circuits are lowered. Once this happens and the processor senses it, the CO detector will activate the alarm.
  • Electrochemical Sensor – quite similar to the metal oxide semiconductor, this sensor triggers its alarm when it detects electrical current changes. Instead of a silica chip, it is equipped with three electrodes dipped in a chemical solution. These electrodes are capable of detecting the presence of carbon monoxide in the air.

How these detectors work will depend on the sensors present. Among these three, the electrochemical sensor is the type most widely used for home CO detectors.

It’s not just elevated levels of carbon monoxide that are detected; CO detectors can also sense when the levels are lower than usual for a prolonged period, as this could mean that the gas is not being dissipated properly.

Fortunately, carbon monoxide levels increase gradually, giving your CO detectors ample time to detect their presence and alert you before it reaches toxic levels.

How Many Carbon Monoxide Detectors are Required in a House?

A potentially fatal mistake plenty of homeowners make is to have only one carbon monoxide detector… in a multistory home. In fact, multiple investigations have proven that this is as bad as not having a CO detector.

Imagine this scenario: the sole detector is found in the ceiling of their living room, the high amount of carbon monoxide is present in the garage, yet they are sleeping soundly in their bedrooms. The only way for that detector to sound the alarm is when the gas reaches the living room, and when this happens, the level of gas in the garage is already dangerously high.

The chances of survival in that situation is significantly lowered.

Ideally, each household should have at least one CO detector. The exception lies in small homes, such as studio-type units, where the detector’s scope is enough to cover the entire space.

Various states also have their own requirements when it comes to having CO detectors at home, but in general, most require one detector for every level. Some states may also require homeowners to mount one or more in specific spots, such as in the sleeping areas or bedrooms, garage, or some distance away from combustion sources.

It’s important for homeowners to check the state requirements when CO detectors are involved.

Where Should You Install Carbon Monoxide Detectors in Your Home?

The constant question that plagues homeowners who want to mount a CO detector in their home is this: where is the best place to install it? What is the perfect height for its installation? Should it be placed high or low?

The height of where a CO detector is mounted matters, as this will be the basis of how well your detector will work. There’s some debate as to where is the best place to mount CO detectors; some say it should be up on the ceiling or on high spots of walls, while others also believe that placing them way up high makes them ineffective.

In general, a good practice is to place your CO detector around five feet above the floor in most living spaces. This height is ideal because it is roughly where your detector can best sense the presence of carbon monoxide quickly, since this gas gets mixed up with air and will take some time to rise up.

If mounting them in your bedroom, you can place them at knee height or almost at the same level as your face when lying down on your bed, if not a bit higher than that. This allows your detector to immediately alert you of the presence of carbon monoxide even while you’re asleep, which is when most carbon monoxide poisonings occur.

Aside from that, you also need to make sure to mount your detectors in a spot where you can easily hear when it sounds the alarm, reach its buttons, and view the built-in screens, if available. It should also be in a spot free from anything that can block the flow of air around it, such as curtains and furniture.

Like we mentioned, each floor of any home should have one or more CO detector installed. Other locations that should have one mounted are:

  • Each bedroom
  • On the hallway of sleeping areas
  • Living room and other living spaces
  • Basement
  • Home office
  • Near the garage
  • Near the kitchen
  • Near a location that has a combustion source
  • In any location required by your state

You might wonder why we don’t recommend placing them in the same room as that of a combustion source, such as inside the kitchen or garage. After all, this is the norm with the usual fire and smoke alarms.

CO detectors will differ. Placing them there can trigger them every now and then, since these sources will emit higher amounts of the gas at startup and this may be sensed incorrectly by the detector.

You should also avoid subjecting your CO detector to these conditions or placing them in these locations, since they will also likely set off your detectors unnecessarily:

  • High humidity
  • Extreme temperatures
  • Attics and crawlspaces
  • Bathrooms
  • In a spot where it will be hit by direct sunlight
  • Spots that are within range of sources of air being blown in certain directions, such as windows that are opened up, vents, and fans
  • Inside cupboards, cabinets, and other similar spaces
  • Dirty or dusty areas
  • Porches

CO detectors may come with guides indicating where they should be mounted. Some detectors function best at a height that they were specifically designed for. Manufacturers may also vary in their mounting recommendations, so it is always best to follow their suggested installation height.

How Far Should Carbon Monoxide Detectors Be from a Furnace?

False alarms are the bane of any homeowner. It’s frustrating to suddenly hear the alarms ring all over your home and send everyone in a nervous panic, only to find out that there’s actually nothing wrong. While it’s a good thing that it’s only a false alarm, you will end up questioning their reliability if this frequently happens.

All home alarms or detection devices are at risk of false alarms, even CO detectors. Fortunately, the instances of it happening for the latter is minimized. This is because the instance of false alarms happening to CO detectors is only limited to when starting up a combustion source, as these sources will release higher amounts of the gas at this time that will quickly disappear.

If you mount a CO detector near a combustion source, or in the same room as one, expect it to be triggered every time you fire up your stove, run your gas clothes dryer, or start up your car in the garage. CO detectors are sensitive, and even those quick bursts of carbon monoxide is enough to trigger the alarm.

Avoiding these false alarms is the reason why CO detectors, as well as other types of household alarms, are recommended to be installed some distance or height away from their potential triggers.

You might ask yourself, how is such a tiny device going to detect an invisible gas if it is placed several feet away from the stove, furnace, heater, or any other carbon monoxide-producing equipment at home?

Don’t worry because this is hardly an issue; CO detectors can detect the presence of carbon monoxide several feet away. Just don’t install them too far away. It is recommended that you place CO detectors a minimum of 15 feet away from most combustion sources, including furnaces.

A good practice is to install those detectors outside the rooms with combustion sources present, including the room where your furnace is located. Just make sure that it is at least 15 feet away from the combustion source. We can’t stress this enough.

Carbon Monoxide Detector Placement Code, Laws, & Requirements by State

In the past, it was up to homeowners to decide if they should get CO detectors installed at home or not – it wasn’t considered an issue if you didn’t. But due to the increasing number of accidental deaths due to carbon monoxide poisoning, most states in the country have required homes to be fitted with CO detectors.

However, you can’t just march into a hardware store and get any detector. You should also know that some states are quite strict – they have to be a pre-approved model by the local fire department, placed in areas specified by the state, installed by a professional connected to the state, and must be functioning and regularly tested.

Some may think that it’s a big inconvenience to follow their state’s guidelines, but what is a little inconvenience if it will save the lives of your entire household, right?

If you’re curious, here are the regulations of some states when it comes to CO detectors:


This is considered the safest state when it comes to carbon monoxide poisoning, and for a good reason – they have stringent requirements when it comes to these devices. And, the rules apply not just to homeowners but also to landlords who lease out their homes or units.

In fact, there are three statutes in the California Health and Safety Code involving CO detectors:

  • 13260 to 13263 (Carbon Monoxide Poisoning Prevention Act of 2010) – requires that CO detectors sold, marketed, and installed in the state must be included in the list of approved CO detectors made by the State Fire Marshal
  • 1569.311 – CO detectors must be present in elderly care and other similar residential facilities
  • 17926 to 17926.2 (Regulation of Buildings Used for Human Habitation) – all dwellings, including single family homes, motels, and hotels must have CO detectors present and in working order. And if you are a renter, you must inform your landlord or real estate agent when the detectors are no longer working or insufficient


Just like California, Maryland also has strict requirements when it comes to having CO detectors at home. In fact, there are also three statutes in the Maryland Code (Annotated) on Public Safety:

  • 12-1101 to 1106 (Carbon Monoxide Alarms) – not only states that these detectors must be present some distance away from equipment that produces carbon monoxide and outside every bedroom, it also does not allow tampering to disable them.

It also allows crafting other related requirements for their home and mandates that anyone who sells a home in the state must inform the buyer of the presence of equipment that use fossil fuel, especially for heating, and if CO detectors are present.

  • 10-702 (Single-Family Residential Real Property Disclosure Requirements) – the disclosure form must indicate if the home has appliances and equipment that use fossil fuel during its operation, such as for heating water, drying clothes, and heating and ventilation, and also if CO detectors are installed
  • 4-117 (Public School Buildings – Carbon Monoxide Detection and Warning) – states that CO detectors must be present in renovated or new public school buildings that have any equipment powered by fuel, including dormitories and fraternity and sorority houses that are linked to public and public schools and post-secondary institutions

New York

The fifth safest state when it comes to carbon monoxide poisoning, New York has one CO detector-related statute.

The New York Executive Law § 378 or Standards for New York State Uniform Fire Prevention and Building Code states that the Prevention and Building Code is mandated to come up with guidelines for the installation of CO detectors in single or multiple family homes or dwellings, including condominium buildings and other similar structures.

The detectors must also meet the standards set by the council in terms of their design, manufacture, and installation. They are also required to be mounted in homes that use appliances and other equipment that possibly emit the gas, as well as in homes that have an attached garage.


Two statutes related to CO detectors are present in Texas:

  • Texas Human Resources Code (Annotated) 42.060 (Carbon Monoxide Detectors) – decrees that family dwellings, as well as day-care facilities, must have CO detectors installed
  • Texas Health and Safety Code (Annotated) 766.003 (Information Relating to Fire Safety and Carbon Monoxide Dangers) – mandates the state to provide information about the correct usage and upkeep of appliances that use fossil fuels, as well as the availability of CO detectors and how they can help people avoid carbon monoxide poisoning


Two of the Florida Statutes are related to CO detectors:

  • 553.885 (Carbon Monoxide Alarm Required) – lists each place where a CO detector must be mounted: within 10 feet of every sleeping area in a home or building constructed on or after July 1, 2008 and also has an attached garage, fireplace, and appliances that burn or operate on fossil fuel
  • 509.211 (Safety Regulations) – in relation to chapter 554 of the Florida Statutes, CO detectors are required to be present in any room or space that has a boiler installed and is found in the same building that has sleeping areas present.

The detectors must also comply with the Underwriters Laboratories, Inc., Standard 2034, or an equivalent, and has been tested by a testing laboratory recognized at a national level and is labeled as such.

These CO detectors must also be connected to the fire detection system of any public lodging establishment.


Compared to those states we already mentioned, Oregon has the greatest number of statutes related to the installation of CO detectors in residential and commercial dwellings. To be exact, six statutes on the Oregon Revised Statues are available:

  • 90.316 (Residential Landlord and Tenant Obligations) – dictates that landlords are obligated to have CO detectors installed in the homes they rent out if these homes have any equipment capable of producing carbon monoxide.
  • 90.320 – declares that any building cannot be inhabited if there is a carbon monoxide-using appliance or equipment present but there are no CO detectors installed
  • 90.325 – mandates tenants of any residential building to test the CO detectors mounted in their rented home at least once a month, and replace the detectors’ batteries when needed. However, they are not allowed to tinker with and remove them
  • 105.836 to .844 (Carbon Monoxide Alarms in Dwellings) – does not allow selling residential homes that have any equipment that can produce carbon monoxide present if these homes do not have CO detectors installed that will cover all sleeping quarters. Also, tinkering with these detectors is forbidden
  • 455.360 (Mandated Carbon Monoxide Alarms) – any commercial building where anyone can sleep in, such as dormitories, motels, and hotels, are required to have CO detectors
  • 476.725 (Standards for Carbon Monoxide Alarms) – the state requires its Fire Marshal to come up with guidelines regarding the basic specifications of CO detectors that may be installed in any home, including design requirements and their regular testing, maintenance, and inspection

For a full list of the states and their requirements and policies involving CO detectors, you can head over to this link.

How to Install a Carbon Monoxide Alarm

Installing a CO detector seems like a straightforward task, like you can just stick it on any surface you choose. This is possible if you use a detector with adhesive strips present. While this is okay, it is better to mount your CO detector using screws.

It’s common that these detectors come with frames or mounting brackets that you can screw onto any surface. But since it involves screws, drilling is involved. Not everyone is comfortable at the thought of using a drill, especially those who are not well-versed in using any construction equipment. This is why even for a seemingly easy task, getting professional help should be one of your options.

Typically, this is how CO detectors are installed:

  1. Identify the best place where it will be mounted
  2. Unpack the detector and install the batteries if using battery-powered ones. If using AC-powered CO detectors, make sure that there is a power outlet near the chosen mounting spot
  3. Remove the base or frame of the CO detector and use it as a guide for marking where the screws of the detector will go in
  4. With the marks as guide, your contractor will use a drill to make holes on the surface where your detector will be placed. For a perfect fit, the contractor will make sure that the drilled holes are of the right size and not bigger than the screws of your detector
  5. Place screw holders inside the drilled holes. These will prevent the screws from becoming loose. Your contractor will use a hammer to make sure that the holders are completely lodged in the holes
  6. Place the frame on the surface and make sure that the screw holes are aligned to the drilled holes
  7. Use the screws to secure the frame in place
  8. Attach the CO detector itself to the frame

Once the CO detector has been installed in your chosen spot, it is always ideal to test it out. These detectors come with test buttons that allow you to do so, and pressing the button will trigger the alarm and cause it to make noise. Make sure to pay attention so that you’ll have an idea of the sound your detector makes when it gets triggered.

Some detectors also allow interconnection, that is, they can be connected to other compatible CO detectors in your home. As a result, they can be set off simultaneously when one of the connected alarms detects the presence of carbon monoxide somewhere in your home. But, making this possible involves tinkering with electrical wiring, that’s why this particular task should only be done by a qualified professional.

Types of Carbon Monoxide Detectors

If you have been window shopping for a CO detector, you might find yourself scratching your head at the various options available on the market. To help you choose, we’ll explain the different types available:

Basic CO Detector

The cheapest one, the basic type doesn’t have all the bells and whistles other CO detectors have – it’s just a straightforward detector. Because it’s a simple model, it will only set you back by around $15 to $20. Fortunately, some models also have a digital display installed that will indicate the carbon monoxide levels, as well as if you need to change its batteries.

Combination Type

If you don’t have both a CO detector and a smoke alarm, the combination type is ideal for you. This type of detector can sense the presence of both carbon monoxide and smoke at the same time with only one device. It also allows you to save money, since you don’t have to buy and install two separate devices. Fortunately, some models only cost $20 to $30, making it a very practical option.

Smart Detectors

We live in the time of rapid technological advancements, so it is expected that CO detectors will also keep up with the times. Not only do we have smartphones or smart watches, we also now have smart CO detectors that allow you to monitor the level of carbon monoxide in your home while you’re out. This type usually comes with both smoke and carbon monoxide sensors and costs $90 to $120 on average.


Although not really for home use, there are also portable CO detectors present. These handheld detectors are normally used by professionals involved in safety inspections, especially in commercial establishments.

In terms of power source, you can choose between:

  • Battery-powered
  • AC-powered or plugged in to an outlet
  • Hardwired to the power supply of your home

Like we mentioned, certain CO detectors can be interconnected to other alarms. If possible, you should go for models with this option. This assures you that your entire household will be alerted in case of an emergency, no matter where they are at home.

CO detectors will greatly affect your chances of surviving carbon monoxide poisoning. That’s why in most cases, it does save lives.

Exceptions apply because some homeowners are negligent with their maintenance. They mistakenly believe that these detectors are failproof and can last forever, that’s why they are lax when it comes to changing the batteries and regular testing to see if their detectors still work.

In fact, carbon monoxide-related deaths in homes with CO detectors are still happening because of such negligence.

This is why it is important not just to mount these detectors at home, but also make sure to keep them well-maintained. They will last long, but not forever, so make sure to change them when needed. That way, you can be certain that your chances of surviving carbon monoxide poisoning, especially while sleeping, are nearly 100%.

And that’s something we should strive for.

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