Every spring, millions of Americans scrub their kitchens, organize their garages, and donate clothes they haven’t worn since 2019. Closets get emptied, refrigerator coils get vacuumed, and windows get washed for the first time in a year. But there is one safety task that consistently gets skipped during the seasonal purge: checking the smoke detectors and carbon monoxide alarms.
These devices are your home’s silent guardians, but only when they work. A dead battery or an expired detector is worse than many homeowners realize because it creates a false sense of security. You walk past the detector every day, assume it would go off if something were wrong, and never find out it hasn’t been functional for months. This spring, take 20 minutes and run through this complete checklist.
Test Every Unit
Press and hold the test button on each smoke detector in your home. A working unit will emit a loud, sustained beep. If nothing happens, or the beep is faint or inconsistent, it is time for a new battery or a full unit replacement. Do not assume a detector works just because it hasn’t chirped recently. Low-battery chirps can be easy to miss, and some units fail silently.
Replace Batteries Annually
Even if your detector passed the test, replace the batteries if you haven’t done so in the past year. The old “change your clocks, change your batteries” rule still applies. Many 9-volt and AA-battery alarms will chirp intermittently when the battery gets low, but don’t rely on that warning. Batteries can drain faster in extreme temperatures, and battery-powered detectors in unconditioned spaces like garages or attics may need more frequent replacement.
Check the Manufacture Date
Smoke detectors have an expiration date, typically 10 years from the manufacture date stamped on the back of the unit. Flip the unit off the ceiling mount and look on the back or inside the battery compartment for a label. If your detector is older than 10 years, replace it regardless of whether it still beeps when tested. The internal sensing chamber degrades over time and may no longer reliably detect smoke even if the alarm sounds during a test.
Check Placement and Coverage
Current recommendations from the National Fire Protection Association call for a smoke detector on every level of the home, inside each bedroom, and outside every sleeping area. If yours are all clustered in hallways, you may have gaps in coverage. Interconnected detectors, which cause all units to sound when one detects smoke, provide the best protection and are required in many new builds in Texas.
Carbon monoxide (CO) is odorless and colorless. You cannot detect it without a working alarm, and exposure can cause symptoms that are easy to mistake for illness, including headache, nausea, dizziness, and fatigue. At high concentrations, CO exposure can be fatal within minutes. This is not a device you want to gamble with.
CO detectors have a shorter lifespan than smoke alarms. Most are rated for 5 to 7 years from the manufacture date. Check the back of each unit and replace any detector that has reached or exceeded its rated life, even if it still responds to the test button. The electrochemical sensor inside degrades over time and may not reliably detect CO levels even when the unit appears functional.
CO detectors should be installed on every level of the home, especially near sleeping areas and in any room with a gas appliance, furnace, water heater, or attached garage. The garage connection is particularly important: many CO poisoning incidents involve vehicle exhaust entering the living space through an attached garage, often without the homeowner’s awareness.
Many modern homes have combination smoke and CO detectors installed as a single unit. These are convenient and reduce clutter, but there is an important caveat: the CO sensing component often has a shorter rated lifespan than the smoke sensing component. A combination unit that is six years old may still pass the smoke test but have a CO sensor that is past its effective service life.
If your combination units are more than 5 years old, consider replacing them even if they pass all audible tests. The cost of a new combination detector is modest compared to the risk of a non-functional CO sensor.
While you are in the mode of testing and replacing, spring is also an excellent time to check a few other safety items that are easy to overlook. If you are new to homeownership and want a broader maintenance checklist, our New Homeowners guide covers the full range of seasonal and ongoing maintenance tasks that keep a home running well:
During a standard home inspection, licensed inspectors check for the presence and general condition of smoke and CO detectors, but a home inspection is not a fire-safety audit. The responsibility for maintaining these life-safety devices falls to the homeowner. What an inspector can tell you is whether detectors are present in the locations required by Texas building code and whether they appear to be functional at the time of inspection.
At Upright Professional Inspections, we make it a point to flag any visible concerns with detectors and help our clients understand what current standards recommend. Whether you are buying a home or maintaining the one you have, we are here to help you make informed decisions. You can also view sample inspection reports on our website to see exactly how we document safety system findings.