Perhaps you have a hardwired smoke alarm that is connected to your electrical breaker. If this is the case, you'll need to make your way to the electrical panel and look for a breaker labeled “Smoke Alarms” or “Central Smoke Alarm.” Turn the breaker to the off position and wait a few minutes before turning it back on.
The circuit breaker for the fire alarm control panel must be painted red and be accessible only to authorized personnel. This illustration shows a locking tab attached to the circuit breaker that prevents it from being shut off inadvertently.
Locate the main breaker panel for your home. Identify which circuit breaker powers your smoke alarms. Each breaker should be labeled, so look for something that says “smoke alarm” or something similar. Turn off the circuit breaker for your smoke alarms.
Several common causes can explain why your hard-wired smoke detector is beeping: Low battery: Even hard-wired smoke alarms have backup batteries that need replacing periodically. A low battery can cause that annoying beeping sound. Dust buildup: Dust and debris inside the smoke detector can trigger false alarms.
The smoke alarm will automatically reset after approximately 8 minutes unless particles of combustion are still present. The “Hush” feature can be used repeatedly until the air has been cleared of the condition causing the alarm. Pushing the Test/Hush button on the alarm will end the hush period.
Checking the Circuit Breaker
Perhaps you have a hardwired smoke alarm that is connected to your electrical breaker. If this is the case, you'll need to make your way to the electrical panel and look for a breaker labeled “Smoke Alarms” or “Central Smoke Alarm.”
Tip: Before working on a hard-wired smoke detector, turn off the main power at your circuit breaker to avoid electrical shock.
Stopping a smoke alarm from beeping is often simple. Get a step ladder and carefully reach for the alarm. Pressing the “Test/Silence” button on the front of the unit should stop it from beeping or chirping. If this doesn't work, grasp the device and turn it counterclockwise.
Can I install a hardwired smoke detector myself? While it is technically possible, it is not recommended. Working with your home's electrical system can be dangerous and complex, best left to a qualified electrician.
Check your garage for the circuit breaker or fuse box. It might also be in a storage room, utility room, the basement, or a hallway. If you can't find your box in one of these areas, look again or see if you can spot where the power connects to your house from outside. Check for your box in the surrounding areas.
Some smoke alarms are provided with both primary power that is hardwired in from the home's electrical system and a secondary battery backup. The secondary battery backup can be either a battery that needs to be replaced at least yearly, or it can be a 10-year sealed battery that does not need to be replaced.
In some cases, smoke isn't even necessary — a hint of burnt food can be enough to set off the detector. Leaving bread in the toaster or popcorn in the microwave for a little too long can send heavy particles into the air, which your smoke alarm picks up.
Smoke detectors do not have their own dedicated circuit breaker. Instead, they are typically connected to a general lighting circuit or a dedicated circuit in the electrical distribution board. Smoke detectors operate on low power, typically consuming around 50-100 milliamps.
Common reasons a fire alarms keeps going off are: Dead or dying batteries. Poor placement, like in kitchens, bathrooms or garages. Interference from airborne chemical compounds, like those released from wet paint.
You may get a false alarm if the battery life is fading or if the detector isn't properly connected. To check the battery, remove the outer casing and check to ensure that the old battery is properly connected. If so, it's a good idea to replace the batteries.
If you're changing the batteries on a hard-wired smoke detector, you should first shut off the power at your circuit breaker. On some models, you can just twist the cover off, while you'll need to snap the cover out of place on others.
Hardwired detectors are usually installed by splicing into a general lighting circuit or outlet circuit. Either a 15-amp circuit (wired with a 14-gauge wire) or a 20-amp circuit (wired with a 12-gauge cable) is acceptable when powering smoke detectors.
The dedicated power circuit breaker shall have a red marking, be accessible only to authorized personnel, and be identified as “FIRE ALARM CIRCUIT”. In addition, the dedicated circuit breaker location must be identified at the fire alarm control unit, NAC power supply, or fire alarm communicator.
Manually pressing and holding the “silence” button on the smoke detector/fire alarm will cause it to stop sounding but not permanently turn it off. On older models, you may need to unscrew the alarm from the wall or ceiling and hold down a button on the back.
Take the smoke detector off its mounting bracket on the ceiling and disconnect the power cable connected to the smoke detector. Remove its battery, then press the “Test” button and hold it down for 15 seconds. An alarm will sound brief, then the alarm will silence.
Things like taking a hot shower or blasting the heat can cause condensation to build up inside the alarm, disrupting the sensor. It can be the main reason for the fire alarm randomly going off at night.