Where to place a carbon monoxide detector in your home

Table of Contents Show

• Carbon monoxide monitor placement
• Carbon monoxide monitor installation and maintenance
• Related articles on SafeWise
• Recent Articles
• What is a carbon monoxide detector used for?
• No, the carbon monoxide detector must not be installed on the ceiling
• Ideally, you should install your carbon monoxide detector near the source of the gas
• Is a carbon monoxide detector mandatory at home?

Just as you should use both door and window sensors with your home security system, a smoke detector and carbon monoxide (CO) monitor should go hand in hand when it comes to protecting your home from smoke, fire, and poisonous gases. Many states require homes to have carbon monoxide detectors, but where and how many you install will vary based on your home’s layout and size.

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To maximize your home’s security against high levels of carbon monoxide, place detectors in several key locations.

• On each level. Each level should have at least one monitor. Don’t forget to include your basement and attic as levels of your home.
• Near each bedroom. Make sure everyone in your home can hear the alarm sound—even if they’re asleep when it goes off.
• Next to attached garages. Cars release carbon monoxide when they’re running, and if a car is left running in your garage for too long, the gas can seep into your home.
• Anywhere manufacturers or state laws recommend. Some carbon monoxide detectors are designed to work in certain areas of your home, so check the manual. Additionally, certain states have specific regulations around CO monitor placement.

Carbon monoxide monitor placement

There’s a common misconception that carbon monoxide monitors should be installed near the floor. This is likely because some standalone units must be plugged in and most outlets are closer to the ground. However, as carbon monoxide is lighter than air and distributes evenly throughout a room, it’s better to install CO detectors at least five feet above the ground or a few feet below the ceiling.

To avoid false alarms and help your monitors accurately identify carbon monoxide levels in your home, make sure you keep them at least fifteen feet away from any fuel-burning appliances—such as a gas-powered stove, oven, or fireplace—fans, vents, windows, and humid rooms, like bathrooms.

Carbon monoxide monitor installation and maintenance

Depending on your preferences, you can purchase carbon monoxide monitors and smoke alarms separately, or buy combined devices that offer both in one. Regardless which route you take, choose an interconnected monitor so when one monitor sounds, the other monitors in your home will also sound.

Once your carbon monoxide monitors are installed, check the levels and test them once a month. If the battery starts running low, replace it immediately. Check out our buyers guide to see our top picks for carbon monoxide monitors.

Related articles on SafeWise

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Written by

Celeste Tholen

Celeste has dedicated her decade-long career to reporting and reviews that help people make well-informed decisions. She oversees editorial strategy and production for SafeWise, with a goal to help everyone find the information they need to make their homes and lives safer. Prior to SafeWise, she worked as an editor and reporter for KSL and Deseret News. She holds a Bachelor's degree in Journalism. In her free time, she volunteers at the local botanical garden and writers for the community newspaper.

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• Where should I install a carbon monoxide detector?

Confused about how to decide where to install your home carbon monoxide detector? Carbon monoxide is a poisonous gas that can emanate from any combustion device, especially heating appliances. For this reason, a carbon monoxide detector can really help to ensure your peace of mind. But the question remains: where should you install a carbon monoxide detector in your home?

What is a carbon monoxide detector used for?

The carbon monoxide detector is a device that emits an alarm when it detects the gas in too large a quantity in a certain room of your home.

Essentially, the carbon monoxide detector is a security system that continuously analyses the ambient air in a room. This helps guard against the dangers of carbon monoxide, a gas that is poisonous and even fatal with prolonged exposure.

Any combustion appliance can emit this gas into the home, whether it is a gas stove, an oil fire or a thermal heater. Since carbon monoxide detectors contain a sensor, they should be placed near where carbon monoxide would be released (in other words, near your heating appliances).

No, the carbon monoxide detector must not be installed on the ceiling

Contrary to popular belief, and often because of the confusion between smoke detectors and carbon monoxide detectors, the latter should not be placed on the ceiling, but preferably on the wall.

It can be very dangerous to install a carbon monoxide detector on the ceiling. To fully understand why, first we need to cover a few key principles.

There is a good reason that we install our smoke detectors on the ceiling: smoke is lighter than air, so it rises quickly. On the other hand, installing carbon monoxide detectors on the ceiling can be very dangerous for one simple reason: carbon monoxide has the same density as air.

This means that carbon monoxide does not naturally rise up to the ceiling, like smoke. Instead, carbon monoxide mixes with the ambient air in the room. This means that the gas becomes most concentrated in the area where the air is circulated: the centre of the room.

So, where should you install your carbon monoxide detector for it to be really effective?

Ideally, you should install your carbon monoxide detector near the source of the gas

Install your carbon monoxide detector in the right place

For it to be most effective, it is important to install your carbon monoxide detector in the same room as your fuel appliance. This means the detector’s alarm will ring at the slightest overshoot of the safe carbon monoxide threshold.

Ideally, you should install your detector 1 to 3 metres from the source appliance, in a horizontal position. The detector must be installed at around eye level, so between 1.5 and 1.7 metres.

However, this is not always possible, depending on the layout of your home. If you run out of space to install your carbon monoxide detector according to these tips (i.e. more than a metre or so from the source and at eye level), another option is possible. You can actually install the detector at a little over a metre from the appliance. However, this is less efficient.

Important to note: you should never place the detector too close to the potential source of carbon monoxide, as this can affect its proper function.

Make sure you can hear the carbon monoxide detector alarm at all times

Especially in a very large or very well soundproofed home, you must also be able to hear the detector's alarm under all circumstances, wherever you are when it rings.

If the room where you place the detector is too far from the room where you sleep, for example, you may not be alerted in due time. This will affect the usefulness of your carbon monoxide detector.

Place the carbon monoxide detector away from ventilation sources

This is to make sure the detector is continuously measuring a sample of the air you breathe at home! To ensure this, try to avoid installing the detector near a ventilation source (window, door, extractor hood, and so on).

Is a carbon monoxide detector mandatory at home?

In the UK, carbon monoxide alarms must currently be installed in all residential buildings with fixed solid-fuel burning appliances.

For your safety, it is wise to install a carbon monoxide detector to avoid potential poisoning. Statistics from the UK’s National Health Service show that there are around 60 deaths from accidental carbon monoxide poisoning in England and Wales each year.

No matter what type of heating you use (wood, gas or oil), the risk of incomplete combustion (the process that causes carbon monoxide to be emitted) is real.

However, there are some basic rules that make it possible to limit the cases of carbon monoxide emissions. These include:

• Maintaining your heating and piping

• Managing your fuel properly

• Keeping your heating appliances in the best possible condition

As the (battery) life of carbon monoxide detectors is not unlimited, it is also important to test your carbon monoxide detector once a year to see if its alarm is still working.

It’s undoubtedly the right move to install a carbon monoxide detector, so that this gas is no longer a potential threat in your home. Home security is not optional, and a carbon monoxide detector keeps you safe from one of the most dangerous gases in the house.

All you have to do is choose the carbon monoxide detector that suits you best: entry-level or high-end, connected or classic, wired or wireless, battery-powered or no-battery, etc. Then, all you have to do is install the detector at home. The good news is that carbon monoxide detectors require no maintenance, aside from regular alarm functionality checks!