How to test smoke and CO alarms room by room, once a month

It's easy to test the alarm you can reach and forget the one over the basement stairs. A fixed route means every alarm gets pressed, and a log tells you in March whether February's test happened.

1. Number the alarms

   Walk the house once and give each alarm a number and a place: 1 main bedroom, 2 hall outside the bedrooms, and so on. The planner lists every spot NFPA counts, so you can check none is missing.

2. Tell the house

   Warn everyone, and the dog, before you start. The test is loud on purpose.

3. Find the test button

   It's the button on the face of the alarm. On a combination smoke and CO alarm, check the label for what the button tests.

4. Print the log

   Print the alarm test log from the planner. Keep it with the house records, or tape it inside a closet door near the stairs.

Source: NFPA, installing and maintaining smoke alarms, checked October 15, 2026.

1. Start at the top

   Start on the top floor and work down, so you finish at the basement alarm at the bottom of the stairs.

2. Press the button once

   A working smoke alarm answers with a loud beep, beep, beep.

3. Listen for the others

   If your alarms are interconnected, USFA says they all sound when one does. Have someone listen at the far end of the house.

4. Write it down

   Date, alarm number, OK or not. One line per alarm.

5. Do the CO alarms the same day

   NFPA says to test carbon monoxide alarms at least once a month too, so they go on the same route.

Source: NFPA, installing and maintaining smoke alarms, checked October 15, 2026; NFPA, smoke alarms, checked October 8, 2026; USFA, smoke alarms, checked October 8, 2026; NFPA, carbon monoxide safety, checked October 15, 2026.

• Loud beep, beep, beep when you press the button: the alarm passed this month's test.
• Nothing when you press the button: change the battery, or replace the whole alarm if it's more than 10 years old.
• A single chirp every 30 or 60 seconds: the battery is low. Change it the same day instead of waiting for the next test.
• Chirping that carries on after a new battery: the alarm has reached the end of its life and needs replacing.
• A chirp from an alarm with a sealed 10-year battery: there's no battery to change, so NFPA says to replace the whole alarm.

Source: NFPA, smoke alarms, checked October 8, 2026; NFPA, installing and maintaining smoke alarms, checked October 15, 2026.

Pick one test each year to do more than press buttons. Change the battery in every alarm that takes a replaceable one, as NFPA advises, using the battery type listed on the back of the alarm. While it's down, read the date of manufacture and check it against the 10-year mark. The guide to reading the date on the back shows where to look.

Source: NFPA, installing and maintaining smoke alarms, checked October 15, 2026; USFA, Don't wait, check the date handout, checked October 12, 2026.

• Tip 01

  Use a broom handle

  If the alarm is high, press the test button with the end of a broom handle instead of climbing. Keep the step stool for the yearly battery change.

• Tip 02

  Write the date on new alarms

  Before a new alarm goes up, write its replace-by date on the side of the base: 10 years from the date printed on the back.

  Source: USFA, Don't wait, check the date handout, checked October 12, 2026.

• Tip 03

  Keep spare batteries with the log

  Buy the battery type printed on the back of your alarms and keep two with the log, so a chirp at 3 a.m. doesn't mean a trip to the store.

  Source: NFPA, installing and maintaining smoke alarms, checked October 15, 2026.

• Tip 04

  Test after work near an alarm

  After painting, fitting a ceiling fan or sanding drywall near an alarm, press the test button. NFPA says never to paint an alarm.

  Source: NFPA, installing and maintaining smoke alarms, checked October 15, 2026.

• Tip 05

  Tick the log even for an OK

  A blank row means the test didn't happen.

This page is one part of a bigger job. The system page puts the parts in order.

• SystemMonthly house checkOne page for the monthly house check: test each smoke and CO alarm, look at the filter, read the water meter, check under the sinks, write one line.8 steps · 7 parts · 1 page to printOpen the system
• SystemSmoke and CO alarm record: dates, batteries and the monthly testNumber every smoke and CO alarm, read the date on the back, note the battery type, then test once a month and tick it off on one printable record.8 steps · 3 parts · 1 page to printOpen the system

• Chapter 01Smoke and CO alarm plannerCount smoke and CO alarms level by level from NFPA's placement list, then get the replace-by date and the next battery change for your alarms.Open the tool
• ProblemNo size printed on my air filter: how to find itThe print on the frame is gone or the slot is empty. Measure the opening, round to the nearest inch, and know when you need a custom size.Read the guide
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• Chapter 01All records toolsPrintable home records with a calculator behind each one: appliance and warranty log, HVAC filter sizes and change dates.Open the chapter

• Installing and maintaining smoke alarms, National Fire Protection Association (NFPA). Checked October 15, 2026.
• Smoke alarms, National Fire Protection Association (NFPA). Checked October 8, 2026.
• Carbon monoxide safety, National Fire Protection Association (NFPA). Checked October 15, 2026.
• Smoke alarms, U.S. Fire Administration (FEMA). Checked October 8, 2026.
• Don't Wait, Check the Date! Replace smoke alarms every 10 years, U.S. Fire Administration (FEMA). Checked October 12, 2026.

Every outside number on this page names its source and the date we checked it. See them all on the sources page. Spotted an error? Tell us.