how many carbon monoxide detectors do I need

Wondering how many carbon monoxide detectors do I need?

The number of carbon monoxide detectors depends on the residence square feet coverage and the position of the CO alarms.

In this post, we’ll learn what are the main sources of CO leaks, how many carbon monoxide detectors you need, and where to install them.

Users need to install carbon monoxide detectors on every level of a building that utilizes burning appliances and devices. The CO detector should be positioned as close as possible to the bedroom and has to be tested every month.

Let’s next learn more about carbon monoxide detectors!

About Carbon Monoxide Detectors

about the carbon monoxide detectors

The Carbon Monoxide (CO) Detector is meant to alert you when there is an unusual amount of the poisoning gas in the air.

The CO is extremely dangerous when inhaled and this is where the detectors come into place in people’s homes.

The main source of carbon monoxide leaks is burning appliances and devices such as:

  • Gas Heaters.
  • Cars in Garages.
  • Fireplaces.
  • Oven and Barbecue.
  • Trash Compactor.
  • Satellite Dish.

The main purpose of the CO detector is to prevent carbon monoxide poisoning by alarming the inhabitants before it’s too late.

The detector device won’t alarm the critical services on its own and users should immediately leave the environment and call 911.

Tip: Every home utilizing gas-fueled appliances should have an installed CO detector!

How Many Carbon Monoxide Detectors Do I Need In Ontario?

how many carbon detector do need

While in some regions of the world you don’t legally need a carbon monoxide detector, in Ontario you need, one when you’re utilizing a burning appliance, a garage, or a fireplace.

The CO detection device should be within or as close as possible to the bedroom.

In Ontario, you need to install a CO detector next to each sleeping area!

According to Ontario’s carbon monoxide awareness news, the carbon monoxide detector batteries should be replaced at least once a year.

In addition, people should protect themselves from CO poisoning by monitoring their health, especially when they’ve been exposed to the gas.

Note: The Ontario Chief, of Emergency Management, strongly recommends testing the carbon monoxide alarm at least once a month.

Ontario – Canada CO Safety Tips

the ontario co safety tips

Recent research shows that in Ontario, more than 65% of the deaths and injuries by carbon monoxide poisoning happened at home.

That should be enough for us to take the following measures seriously:

  1. Install CO detector near sleeping areas.
  2. There should be a CO detector on every level.
  3. Licensed technician’s inspection of burning appliances.
  4. Older owners of CO alarms should receive help from families to inspect their devices.
  5. Replace the carbon monoxide alarm every 10 years.
  6. When the alarm goes off, leave the house and call 911!

An inspection of the burning appliances should be performed by the contractor.

For hotels and apartment buildings, a carbon monoxide detector should be installed near bedrooms and in the service room.

Tip: The carbon monoxide alarm sounds different from the smoke alarms!

How Many Carbon Monoxide Detectors Do I Need In California?

how many carbon monoxide detector

Accepted from July 1, 2011, there is a phased requirement for ALL dwellings to include carbon monoxide alarms.

According to the California Real Estate Inspection Association, the CO detectors should be close to sleeping areas or at least one per level.

Each carbon monoxide detector covers from 400-1,000 square feet.

Hence, you’ll need to install carbon monoxide detectors respectively to the covered square feet by the facility and coverage area of the device.

The CO detectors last up to 6-7 years after which, the devices should be replaced with a new unit of the same model.

In contrast, batteries should be replaced every 6 months. In the meantime, users need to perform at least one test alarm per month to justify the functionality of the device.

California Residential Code (CRC)

the california residential code

According to the California Residential Code (CRS) carbon monoxide detectors, as well as smoke alarms, should be installed throughout the residence.

The number of detector devices depends on the residential area and the carbon monoxide detector’s coverage.


  • To cover 3,000 square feet of residential area you need 3 CO alarms.

Every facility that utilizes machinery or any sort of gas to provide repairs or to store such appliances should be provided with a carbon monoxide detector.

Alert: If multiple CO detectors are installed they need to be interconnected.

The CO Detector Inspection Requirements

co detector inspection requirements

The owners of businesses that utilize burning appliances should be prepared to face an inspection to justify the availability of CO alarms.

Such an inspection could be arranged or spontaneous so let’s next take a look at what users need to be prepared with.

According to the carbon monoxide regulations, users should note the following:

  1. The carbon monoxide detectors should be installed prior to the inspection date.
  2. The CO detectors should be available to be inspected.
  3. An adult should be available to provide access for the final inspection.
Note: The fee of having the CO detectors not installed at the time of the inspection is about $100.

The Top 4 Best Places For CO Detectors!

top 4 best places

Now when we know how many carbon monoxide detectors are necessary let’s proceed with unwrapping the best places to install these devices.

The recommendation is to attach the carbon monoxide to the wall since the CO does not sink nor rise in the air.

Here are the best places to install a carbon monoxide detector:

1.   In Each Sleeping Room

The best possible place to install a carbon monoxide detector is in each sleeping room/is close to the door.

Whenever there is a gas leak, the alarm should sound indicating a high volume of the poison gas in the environment where people sleep.

2.   In Corridors

The best next place to position a carbon monoxide detector is in corridors, again as close as possible to a bedroom door.

Users should position the CO detectors on every level of the building and if possible outside each bedroom.

3.   In Basements

in the the basements

Another great consideration for a carbon monoxide detector is the household basements.

The recommendation is to have a CO detector in a basement where burning or gas-fueled appliances are being utilized.

In such cases, the detector alarm should be positioned in the immediate vicinity of people.

4.   In Garages

The carbon monoxide should be positioned near garages, again in a way that it would be possible for people to easily hear the alarm.

For connected garages, the carbon monoxide detector is also necessary, especially when the garage is hosting a car.

Note: It’s almost impossible to detect carbon monoxide leaks without a detector!

Carbon Monoxide Detector False Alarms?

co detectors

There are several reasons why your CO detector would sound false alarms:

  • It could be incidental when the alarms are not frequent.
  • CO travels through walls, the gas could have come from the neighbor!
  • A low battery of the CO detector.

In most cases these devices are silent. In case you continue to hear sounds from your CO detector, replace the batteries or the entire device to solve the problem for good.

Quick Recap:

Thus, you need as many carbon monoxide detectors, as respectively to the square feet, your residence is covering. The carbon monoxide detectors cover up to 1,000 feet and should be installed as close as possible to the sleeping areas.

Final Thoughts:

Now that you know how many carbon monoxide detectors do you need you’re ready to position them and prevent the possibility of CO poisoning.

It’s important to replace the batteries of your carbon monoxide detector every 6 months but be aware that some devices use a lithium battery lasting up to 6 years. Such detectors are replaced as a whole.

We hope that this post was helpful for you and that you’ve learned everything about the number of CO detectors that you need.

To find more relevant content, make sure to check our blog!

Nicole B