Carbon Monoxide Detector Placement in Columbus Homes: What Ohio Code Requires
Good carbon monoxide detector placement starts at the bedrooms and works outward. Ohio’s residential code sets the minimum, and federal safety agencies recommend a few more spots on top of it. If your only alarm sits in the basement next to the furnace, the people sleeping upstairs are the farthest from the warning.
Carbon monoxide (CO) is a colorless, odorless gas that gas furnaces, water heaters, ranges and cars all produce. The CDC warns that people who are asleep can die from CO before they have symptoms, and that’s why the code puts the sleeping areas first.
What Ohio code requires for CO alarms
Section R315 of the Residential Code of Ohio sets the rules for one- and two-family homes:
- New homes need CO alarms when the dwelling has a fuel-fired appliance, an attached garage, or both.
- Alarms go outside each separate sleeping area, in the immediate vicinity of the bedrooms.
- If a fuel-burning appliance sits in a bedroom or its attached bathroom, an alarm goes inside that bedroom.
- Alarms must be listed to UL 2034 and installed per the manufacturer’s instructions. Combination smoke and CO alarms are allowed.
Why a furnace replacement can trigger the requirement
Section R315.2.2 also covers existing homes. When a home with a fuel-fired appliance or attached garage needs an approval for certain work to be done, the whole dwelling unit has to get CO alarms placed as the code requires for new homes. That list includes adding or altering a bedroom, altering the area just outside a bedroom, work on an attached garage, and adding, repairing or replacing a fuel-fired appliance.
A new gas furnace or water heater that needs an approval can bring your alarms up to current code. Ask your installer how they handle it before the work starts.
Recommended carbon monoxide detector placement by floor and room
The residential code sets the minimum for CO detector placement. Federal safety agencies recommend going further, and the table below puts both side by side.
| Location | Required or recommended | Source |
|---|---|---|
| Outside each separate sleeping area. | Required by Ohio code. | Residential Code of Ohio R315.3. |
| Inside a bedroom with a fuel-burning appliance. | Required by Ohio code. | Residential Code of Ohio R315.3. |
| Each level of the home, including the basement. | Recommended. | EPA and CPSC. |
| Near the sleeping areas, if you only have one alarm. | Recommended. | EPA. |
| Alarms linked so they all sound together. | Recommended. | CPSC. |
| Battery or battery backup on each alarm. | Recommended. | CPSC and CDC. |
The EPA says each floor of the home needs a separate detector. If you only have one, it belongs near the sleeping areas, and it has to be loud enough to wake you. The CPSC recommends alarms on each level and outside sleeping areas, and it says interconnected alarms are best because when one sounds, they all sound.
Height and exact position within a room come from the alarm’s instructions, since Ohio code ties installation to the manufacturer. Keep the booklet for the detector with your house papers.
Smoke alarms and CO alarms do different jobs
The EPA points out that smoke alarms and CO alarms can look alike but detect two separate hazards, so you need both. Ohio code lets a combination unit stand in for either one, provided it carries both the UL 217 and UL 2034 listings. Check the label before you swap a smoke alarm for a combination model.
How long a CO alarm lasts
Test your alarms and change batteries on the schedule in the booklet. The sensor wears out over time, so the CDC says to replace the detector per the manufacturer’s instructions or at five years.
An alarm warns you about CO that’s already in the house. A yearly furnace check keeps it from building up at the source, and our furnace tune-up checklist covers that visit. Our post on cracked heat exchanger symptoms explains one way a furnace can leak CO. Homes with a boiler can also read our guide on boiler carbon monoxide safety.
Frequently asked questions
How many CO detectors does my house need? Ohio code requires one outside each sleeping area. The EPA and CPSC recommend one on each level as well, so a two-story house with a basement usually needs at least three.
Should I put a CO detector next to my furnace? Follow the placement guidance in your alarm’s booklet. Protecting the sleeping areas comes first, and a basement alarm adds coverage on that level.
Do I need a CO alarm if my home is all-electric? Ohio code also applies to homes with an attached garage. If you have one, you need CO alarms outside the sleeping areas even when every appliance runs on electricity.
How often should I replace a CO detector? The CDC says to follow the manufacturer’s instructions or replace it at five years.
Can a combination smoke and CO alarm meet Ohio code? Yes. Section R315.4 allows combination alarms in place of CO alarms, as long as the unit is listed to both UL 2034 and UL 217.
Good carbon monoxide detector placement protects your family while they sleep, and an annual furnace inspection keeps CO from building up at the source. To schedule furnace service and safety checks anywhere in Central Ohio, call Ohio Heating at 614-863-6666 or request a visit at ohheating.com.