Carbon monoxide (CO) detectors should be located outside each sleeping area, on every level of the home (including the basement), and near—but not right next to—fuel‑burning appliances, generally at about eye level on a wall or on the ceiling away from corners, vents, and windows.

Key places in the home

  • Outside every bedroom or sleeping area so the alarm can wake people at night if CO builds up.
  • On every level of the home, including the basement, and in main living areas like hallways or living rooms where people spend time.
  • Near potential CO sources such as gas furnaces, boilers, fireplaces, and gas water heaters, typically within about 10–20 feet but not immediately adjacent to avoid false alarms.
  • Near the door between an attached garage and the house (inside the home side), not inside the garage itself.

Height and mounting tips

  • Wall mounting: place the detector about 5 feet above the floor, roughly at eye level, so it can sense CO in the breathing zone and stay easy to test and read.
  • Ceiling mounting: if mounted on the ceiling, keep it at least 12 inches away from any wall and out of corners where air can stagnate.
  • Avoid blocking the detector with curtains, furniture, or cabinets, which can prevent air from reaching the sensor.

Places to avoid

  • Do not place detectors right next to or above fireplaces, stoves, or other flame‑producing appliances, or within about 10–15 feet of them, as normal trace CO or heat can cause nuisance alarms.
  • Avoid locations within a few meters of doors or windows, in bathrooms or other very humid spaces, in direct sunlight, or right by fans, vents, or extractors where strong air currents can dilute or divert CO.
  • Do not install detectors in dusty workshops or in garages themselves, where conditions can damage the device or cause frequent false alarms.

Extra safety practices

  • Follow the specific manufacturer’s instructions for each model, as they may have particular requirements for placement and mounting.
  • Test CO detectors at least monthly and replace batteries regularly; replace the entire detector according to its rated service life (often 5–10 years) to ensure continued protection.

Information gathered from public forums or data available on the internet and portrayed here.