How often to test smoke + co detectors in an Airbnb

Every 90 days (~3 months). Cost: $0–$20. DIY-friendly.

The compliance task most hosts get wrong

Testing smoke and CO detectors is non-negotiable in a short-term rental. It is the one maintenance item that simultaneously protects your guests, your insurance coverage, and your Airbnb listing standing. And it is also the one that most operators do casually, infrequently, or not at all — usually because everything seems fine until it isn’t.

Here is what nobody tells you: Airbnb’s policy isn’t ambiguous. Hosts must have working smoke alarms in every required area, working CO detectors if there are fuel-burning appliances, and a documented record of testing. If a guest complaint or insurance claim ever surfaces and your testing log is empty, you have a problem.

The 90-day cadence

Test every smoke and CO detector quarterly — every 90 days — at minimum. That is the cadence both NFPA and most state codes recommend, and it dovetails neatly with the natural quarterly rhythm of STR operations.

A quick test is exactly that: press the test button, listen for the chirp pattern, move on. The whole property takes 10 minutes if there are six detectors and you have a step ladder pre-staged. If you are remote-managing the property, this becomes the cleaner’s job — assign it specifically and check it during your next walk-through.

Battery replacement is a different cadence. Most modern detectors are 10-year sealed-battery units now, but if yours have replaceable 9-volts, swap them every 6 months on the same dates you flip the mattress (so you remember).

How to actually test correctly

1. Press and hold the test button until the alarm sounds. Single chirps are not the alarm — that is a low-battery signal. The alarm is a continuous, much louder pattern.
2. Smoke detectors should beep three times (T3 pattern). CO detectors should beep four times (T4 pattern). If the pattern is wrong, the detector is malfunctioning.
3. Use a smoke aerosol can for an annual full test (Sperry Instruments and others sell $10 cans). The button-only test confirms the speaker works; the smoke can confirms the sensor works.
4. Document the test. Take a phone photo of the detector with the test date written on a sticky note. Store these in a dated folder. This is your insurance evidence.
5. Replace any detector older than 10 years. Sensors degrade. Look at the manufacture date on the back — not the install date.

What to do when one fails

Don’t wait. Replace immediately, before the next guest checks in. A $25 First Alert dual-sensor smoke detector and a $40 Kidde combo CO/smoke detector will cover most STR needs. If you are remote, keep two spares in the supply closet so a cleaner can swap on the spot.

If a detector is hard-wired and chirping erratically, it is not always the battery. Hard-wired detectors share signal lines, so one failed unit can take down the whole chain. Replace the chirping one first; if the chirp jumps to another, the wire harness needs an electrician.

Hand-off script for cleaners

Add this exact line to the cleaner SOP:

“After each turnover, press and hold the test button on every smoke and CO detector for 5 seconds. Photograph each detector with today’s date. If any detector chirps slowly or fails to alarm, message me before guests check in.”

Then audit. The first month, ask for the photos. The second month, spot-check. By month three, it is a habit.

Signs you waited too long

• Detectors chirping during a guest stay (one-star review territory)
• Detectors that have visible yellowing (sensor degradation)
• A detector that no longer responds to the test button
• A combo CO/smoke detector older than 7 years (CO sensors degrade faster than smoke sensors)

Related tools

• Maintenance schedule generator — schedule this every 90 days across all your properties
• Cleaner dispatch — bake the detector test into the cleaner SOP

FAQ

Last verified 2026-05-08.