Your home's smoke detectors are a critical safety component that can help alert you to potential fire hazards. It is critical that the alarms work and function properly. Normally, the alarms should be silent unless smoke is present. A chirping sound typically indicates that there is a problem with the battery or the wiring in the alarm.
The most common reason a smoke detector chirps is because its battery is getting low or weak. Depending on the make and model of your smoke detector, you may also notice a red LED light that blinks intermittently along with the chirping sounds. Replace the old battery with a fresh one, and the chirping should stop. Use a nonrechargeable battery; according to the website Only Batteries, rechargeable batteries have a short lifespan and fully self-discharge in two months. Check and replace the batteries in your smoke detectors roughly every six months to ensure that they all remain powered and operational.
If you just put in a fresh battery and the smoke alarm is still chirping, then you should troubleshoot some potential problems. It could be possible that the connection between the battery terminals and the battery itself is bad. This could be because the battery is loose or the terminals are dusty. Blow out any dust in the battery bay, and brush the terminals with a battery terminal brush. Snap the fresh battery back in, and make sure the battery bay lid is fully closed.
Improper wiring may cause a chirping noise. For example, for AC alarms, the battery may chirp if the interconnect wire is grounded, according to the website First Alert. Chirping may also occur due to power surges. Unless you are an electrician or are otherwise adept at handling electrical and wiring problems, you should consider calling in an expert to resolve any potential smoke detector wiring issues.
Depending on your smoke detectors, you may also need to reset the system. This process may vary by smoke detector. Read your smoke detector's manual before proceeding; you may, for example, have to remove the battery and hold the "Test" button down for a short interval to reset the alarm. Always keep safety in mind when checking your alarms. Fully remove the power source to your alarms before you perform maintenance on them to avoid any electrical shocks or damage. If you are unsure as to how to proceed, call an expert to assist you.