This guide shows home owners how to place, mount, connect and maintain battery or battery‑backed smart smoke and carbon‑monoxide (CO) alarms. It focuses on units you can install yourself (battery or sealed 10‑year battery models and battery smart alarms that use a manufacturer app). It does not cover hard‑wired alarm replacement — for that, follow the manufacturer and hire an electrician if required.
Keep alarms away from cooking
Place smoke alarms at least 10 feet from cooking appliances to reduce nuisance alarms; if that isn’t possible choose a photoelectric or nuisance‑resistant model. ([usfa.fema.gov](https://www.usfa.fema.gov/gallery/pictographs/pictograph03.html))
What you will need
- Your smart smoke/CO alarm(s) (battery or sealed 10‑year battery models).
- Smartphone with the alarm maker’s app installed.
- Step ladder, screwdriver (if mounting plate uses screws), fresh batteries if the alarm needs replaceable ones.
- Measuring tape or a short rule to check distances from walls and cooking areas.
Steps
- Plan locations. Put alarms on every level of the home (including the basement), inside each bedroom and outside each sleeping area. On floors without bedrooms, place one in the living room or near the stairway. This layout is the standard safety recommendation. ([apps.usfa.fema.gov](https://apps.usfa.fema.gov/pdf/efop/efo49772.pdf))
- Pick the precise mounting spot. Install on the ceiling or high on a wall. If wall mounted, position the top of the alarm 4–12 inches below the ceiling; on sloped ceilings mount near the highest point but follow the manufacturer’s guidance for exact placement. Avoid installing within about 10 feet of cooking appliances to reduce nuisance alarms. ([nfpa.org](https://www.nfpa.org/-/media/project/storefront/catalog/files/home-fire-safety/smoke-alarms/smoke-alarm-installation-guide-print.pdf))
- Choose the right alarm type for tricky spots. If you must put an alarm close to the kitchen, choose a photoelectric model or a unit listed for nuisance resistance (some codes and standards require it near cooking areas). When in doubt, check the product listing or local rules. ([law.cornell.edu](https://www.law.cornell.edu/cfr/text/24/3280.209))
- Mount the unit. Mark the mounting plate location, secure the plate per the manufacturer (screws or adhesive as supplied), then attach the alarm. For battery models, insert fresh batteries or confirm the sealed battery is active. Do not paint or cover the alarm. ([nfpa.org](https://www.nfpa.org/-/media/project/storefront/catalog/files/home-fire-safety/smoke-alarms/smoke-alarm-installation-guide-print.pdf))
- Connect the alarm in the app and enable wireless interconnect. Open the manufacturer app, follow the in‑app setup (often scanning a QR code on the device), connect the alarm to your Wi‑Fi or to the device’s required hub, and enable wireless interconnect if available so all alarms in the home sound together. Many smart alarms use a separate low‑power radio for interconnect so alarms can still communicate even if Wi‑Fi drops. Follow the specific maker’s steps. ([support.firstalert.com](https://support.firstalert.com/s/article/Ways-to-Interconnect-Alarms))
- Test right away and test monthly. Use the unit’s test button and the app test routine to confirm local sounding and interconnect behavior. Test monthly and after any battery change or app update. Replace entire alarms at the end of their service life (most recommend replacement at 10 years). ([usfa.fema.gov](https://www.usfa.fema.gov/prevention/home-fires/prepare-for-fire/smoke-alarms/))
Tips & warnings
- Do not remove batteries to silence nuisance alarms; use the hush/hush feature if available and address the cause. Removing a battery disables life‑saving protection. ([usfa.fema.gov](https://www.usfa.fema.gov/prevention/home-fires/prepare-for-fire/smoke-alarms/))
- Keep alarms away from bathrooms, near ducts, or in very dusty/greasy areas that can cause false alarms. Clean dust from the unit periodically per the manual. ([nfpa.org](https://www.nfpa.org/-/media/project/storefront/catalog/files/home-fire-safety/smoke-alarms/smoke-alarm-installation-guide-print.pdf))
- Smart alarms from different brands often can’t interconnect; if you want all alarms to ring together, use compatible models or follow the manufacturer’s bridging guidance. ([support.firstalert.com](https://support.firstalert.com/s/article/Ways-to-Interconnect-Alarms))
- If your home has hard‑wired alarms or interconnect wiring, don’t attempt to alter wiring yourself — use a licensed electrician or the manufacturer’s recommended installer. ([usfa.fema.gov](https://www.usfa.fema.gov/prevention/home-fires/prepare-for-fire/smoke-alarms/))
Installing battery or battery‑backed smart smoke/CO alarms correctly gives you connected alerts and reliable coverage without touching household wiring. Follow the manufacturer’s instructions for your exact model, test monthly, and replace units at the end of their service life to keep your family safe.
Source & rights: Research sources used under their site terms. This article paraphrases official guidance from the U.S. Fire Administration, NFPA and manufacturers; follow your alarm maker’s instructions for model‑specific steps. Source materials remain subject to their respective rights and usage terms. Source 1: U.S. Fire Administration — Smoke Alarms Source 2: U.S. Fire Administration — Where to put a smoke alarm (pictograph)
