Smoke FAQs
What is the difference between a smoke detector and a smoke alarm?
The terms smoke detector and smoke alarm are frequently misunderstood. A smoke detector is powered by a fire alarm control panel and has a separate notification device. A smoke alarm can be hard-wired 120VAC or battery powered. The notification aspect is internal to this device.
Ionization smoke detection vs. Photoelectric type smoke detection – what is the difference?
There are generally two types of smoke detection devices- ionization smoke detection devices and photoelectric type smoke detection devices. Smoke particles of a varying number and size are produced in all fires. Ionization technology smoke detection devices are generally more sensitive than photoelectric technology smoke detection devices at sensing small particles, which tend to be produced in greater amounts by hot, flaming fires that are consuming combustible materials rapidly and may spread quickly. Sources of these fires may include paper burning in a wastebasket, or a grease fire in the kitchen. Photoelectric smoke detection technology is generally more sensitive than ionization smoke detection technology at sensing large smoke particles, which tend to be produced in greater amounts by smoldering fires, which may smolder for hours before bursting into flame. Sources of these fires may include cigarettes burning in couches or bedding.
It is recommended that alarms are replaced after 10 years. Why does the National Fire Protection Association (NFPA) recommend that home smoke alarms be replaced after 10 years?
Smoke alarms have a limited life. Although each smoke alarm and all its parts have passed many stringent tests and are designed to be as reliable as possible, any of these parts could fail over time. Therefore, you must test the devices weekly/monthly depending on the manufacturer’s requirements. The unit should be replaced immediately if it is not operating properly. The performance of smoke alarms older than 10 years may be degraded. To ensure your family’s safety, all smoke alarms and detectors need to be replaced after the end-of-life audible alarm signal, differing from the audible alarm signal, is activated and smoke/CO combination alarms need to be replaced after the end-of-life audible alarm signal, differing from the audible alarm signal, is activated or 10 years from the date of manufacture whichever comes first. All smoke alarms need to be replaced every 10 years.
What is the proper placement of smoke alarms?
It is important that you have the proper placement for your smoke alarms. Install your alarms at least 20 feet from appliances like furnaces and ovens, which produce combustion particles. Alarms should be at least 10 feet from high humidity areas like showers and laundry rooms, and at least 3 feet from heat/AC vents. Be sure to install a smoke alarm in each bedroom, and one at the top of each stairwell.
I get a false alarm from my smoke alarm. Why does my smoke alarm sound when I can’t see smoke?
Any of the following situations may cause nuisance (false) alarm from your smoke alarm:
- The cover or sensor chamber may be covered by dust or dirt. Alarms may look clean, but dust can accumulate inside the cover, even in newly built homes. Gently vacuum your smoke alarm regularly using the soft brush attachment.
- Insects may have clogged the sensor chamber. Clean the smoke alarm with the soft brush attachment on your vacuum. If there are still insects in the area, to prevent repeat problems, clean and treat the surrounding area with insect repellent (DO NOT SPRAY THE SMOKE ALARMS ITSELF).
- Or You may have experienced a power interruption. Hardwired smoke detection devices may sound briefly when power is interrupted then restored.
- If you have hardwired smoke detection devices, you may have a loose electrical connection on your AC or AC/DC smoke alarm. In AC or AC/DC smoke alarms, loose connections can intermittently disconnect power to the smoke alarm. The effect is the same as a power failure. When power is restored, the units may sound briefly.
Why doesn’t my smoke alarm sound when I push the test button?
It is important that you test your smoke alarms weekly/monthly. When you are testing your smoke alarm, there are a number of reasons why the alarm might not sound. You may not be holding the test button down long enough. Try holding it down for up to 10 seconds (20 seconds on photoelectric models.) Another reason is that your battery may not be installed properly or snapped all the way in place. Even if the alarm sounded briefly when the battery touched the terminals, you still need to make sure it is snapped securely in place. If the battery is loose, in cannot power the smoke alarm properly. After installing new batteries, be sure to test your smoke alarm. Your device may have lost primary AC power. AC and AC/DC units will have a power indicator light (red or green) that shines continuously when they are receiving electrical power. And finally, if you have a 10-year model, the smoke alarm may not have been properly activated. If the tab broke away before the alarm was activated, you can use a toothpick to move the switch over to test the alarm.
Why does my smoke detector go into alarm when I install a battery or turn on the AC power?
It is normal for the smoke alarms to go off and sound briefly (up to 5-10 seconds) when you install a new battery or they are powered up. If the alarm continues to go off and no smoke is present, the cause may be:
- There may be insufficient battery power. Try another battery.
- Problems with voltage or insufficient electrical power (brown out) may cause a continuous weak sounding alarm. For AC or AC/DC models, temporarily disconnect power at the service panel until the brown out is over. If you do not restore the AC power, your smoke alarms cannot warn you of a fire.
- Incompatible warning device. If an incompatible alarm or auxiliary device is linked into a series of AC or AC/DC smoke alarms, it may cause the system inadvertently go off
My smoke alarm keeps chirping, even with a new battery. What is causing this?
There are a number of possible causes for your smoke alarm to keep chirping even with a new battery.
- It is possible that your smoke alarm “silence” button was pushed by mistake. The alarm will now “chirp” once a minute for up to 15 minutes before resetting.
- Additionally, Are you sure it’s the smoke alarm? Funny to ask, but other devices have similar low battery chirps or warning tones.
- Even “new” batteries may not be fresh. If batteries are stored, especially in cold areas like refrigerators, they lose their charge more quickly. Always check the freshness date on the package when buying new batteries. Keep plenty of replacement batteries on hand so that you are sure to always be protected by your smoke alarms
I’m ready to change my smoke alarm battery – Does it matter what replacement batteries I use?
Check your User’s Manual or the nameplate on the back of the alarm. Different smoke alarms use different kinds of batteries – 9v, AA, AAA – it all depends on the specific model you have. Never use rechargeable batteries because they may not always provide a consistent charge.
I lost my smoke detection device owner’s manual. How can I get a new one?
Smoke detection devices owner’s manuals are available online for download at no cost. Please have your smoke detection device’s model number handy when requesting a replacement owner’s manual.
How long will the battery last in my smoke alarms?
Actual battery service life depends on the design of your smoke or carbon monoxide detection device and the environment in which it is installed. All kinds of alarm batteries specified in the user’s manual are acceptable replacement batteries. Regardless of the manufacturer’s suggested battery life, you MUST replace the batteries immediately once the unit starts “chirping” (the “low battery warning”).
Carbon Monoxide FAQs
For additional information see NEMA BS 30003-2022 “Applications Guide for Carbon Monoxide Alarms and Detectors.”
What causes carbon monoxide? What are some common sources of carbon monoxide?
Carbon monoxide (CO) is a byproduct of incomplete combustion of fossil fuels. Common causes of carbon monoxide production can be gas or oil appliances like a furnace, clothes dryer, range, oven, water heater, or space heaters that are not working or vented properly. When appliances and vents work properly, and there is enough fresh air in your home to allow for complete combustion, trace amounts of CO produced by these sources are typically not dangerous. However, there are common conditions that can cause CO levels to rise quickly:
- Appliance malfunction, i.e., the heat exchanger on your furnace cracks.
- Vent, flue, or chimney is blocked by debris or even snow.
- Fireplace, wood burning stove, charcoal grill or other source of burning material is not properly vented.
- Vehicle is left running in an attached garage and carbon monoxide seeps into the house.
- Several appliances running at the same time and competing for limited fresh air can be a cause of carbon monoxide buildup. This condition can result in incomplete combustion and produce CO, even if all appliances are in good working condition.
What is carbon monoxide?
This invisible, odorless gas is a common by-product of incomplete combustion of fossil fuels. Carbon monoxide is produced when fossil fuels like wood, coal, charcoal, gasoline, kerosene, natural gas, or oil burn. Because of the way that your body reacts to carbon monoxide, it is a deadly gas that must be avoided to prevent poisoning.
Is carbon monoxide heavier than air? What is the diffusion of carbon monoxide in air?
Carbon monoxide is not heavier than air. The molecular weight of CO is 28 grams per molecule (g/mol), whereas the molecular weight of air is approximately 29 g/mol. Because carbon monoxide is almost identical to the molecular weight as air the diffusion of carbon monoxide in air is relatively even, meaning that a source of carbon monoxide can distribute the gas evenly throughout the room and house. When installing a carbon monoxide alarm, choose a location where the alarm will stay clean, and out of the way of children or pets. See User’s Manual for specific installation requirements.
What are the symptoms of carbon monoxide poisoning?
The symptoms of carbon monoxide poisoning are important to be able to recognize. If you suspect that you or someone else is experiencing sickness as the result of exposure to carbon monoxide, get to a well-ventilated area immediately and contact emergency services. Symptoms of mild carbon exposure can include: slight headache, nausea, vomiting, fatigue, and flu-like symptoms. Symptoms of medium carbon monoxide exposure can include: throbbing headache, drowsiness, confusion, and fast heart rate. Symptoms of high exposure can include convulsions, unconsciousness, heart and lung failure. Exposure to high concentrations can lead to brain damage and death.
Why is carbon monoxide dangerous?
What is the cause of carbon monoxide poisoning? Carbon monoxide can be extremely dangerous because CO robs your blood of oxygen. When you inhale carbon monoxide, it bonds with the hemoglobin in your blood, displacing life-giving oxygen. This produces a toxic compound in your blood called “Carboxyhemoglobin” (COHb) which is the source of carbon monoxide poisoning. Over time, exposure to CO can make you feel sick or worse, victims exposed to sufficiently high levels of carbon monoxide can suffer brain damage, or even die. According to the Journal of the American Medical Association (JAMA), 1500 people die each year because of carbon monoxide poisoning, and another 10,000 become ill. Carbon monoxide is dangerous since you can’t see, smell, or taste the gas. Because you can’t sense it, carbon monoxide can poison you before you even know it’s there.
What are unsafe levels of carbon monoxide?
Are there safe carbon monoxide levels? Determination of unsafe levels of carbon monoxide is different for each person. Since carbon monoxide is a poison, it affects everyone at different levels. Age, size, and health are other factors that can determine the effect CO has on them. You should contact your own physician for advice regarding the issues of safe carbon monoxide levels. Everyone is at risk at some level from carbon monoxide poisoning, but some people are more vulnerable than others. Unborn babies, infants, children, seniors, and people with heart or lung problems may be at higher risk from carbon monoxide poisoning for a variety of reasons. Be sure to install carbon monoxide detect ion devices for protection against unsafe levels of carbon monoxide.
What does “Move to Fresh Air” printed on my carbon monoxide alarm mean?
The phrase “Move to Fresh Air” that is printed on the face of newer carbon monoxide alarms is a reminder to move all family members to a well-ventilated area with fresh air if the alarm sounds. Please note that this does not mean that you should unplug or move the CO alarm itself. When an alarm sounds, make sure that everyone in the building is evacuated to an area with fresh air.
What should I do when the carbon monoxide detection device sounds?
Silence the device. Call your emergency services, fire department, or 911 and tell them your carbon monoxide detection device has triggered. Move everyone immediately to fresh air outdoors or by an open door or window. Do a head count to check that all persons are accounted for. Do not reenter the premises or move away from the open door or window until the emergency services responder has arrived, the premises have been aired out, and your carbon monoxide detection device remains in its normal condition.
Why didn’t the emergency responder find CO gas after an alarm?
If your carbon monoxide detection device went off, it detected a dangerous level of CO gas. Here are some reasons why a responder may not find CO during an investigation:
- Carbon monoxide gas dissipated in fresh air. If windows and doors open before a responder arrived, the same concentration of CO gas may no longer be present. Be safe first and vent dangerous carbon monoxide gas to the outside. The responder can try to recreate the conditions.
- The alarm may have been caused by an on-again, off-again problem. CO detection devices measure gas exposure over time, so the exact conditions that cause an alarm may be difficult to duplicate in an investigation.
Will carbon monoxide alarms detect explosive gas leaks?
No, a single function carbon monoxide alarm reacts to carbon monoxide only. To detect explosive gas, you need an explosive gas detector. Different kinds of explosive gas can be detected, and it is recommended that any home that utilizes natural or propane gas have at least one explosive gas leak detector.
What is the life of a typical carbon monoxide detection device?
How long will a CO alarm last? In general, after 10 years any alarm should be replaced with a new CO alarm. Alarms may have an actual life span that is shorter due to environmental conditions and may need to be replaced sooner. UL 2034 requires the CO alarm to indicate an audible end-of-life signal that is different from the alarm signal. UL 2075 requires the CO detector to send an end-of-life signal to the control unit and the remote supervising station. The end-of-life signal is triggered either by an internal timer or by a self-diagnostic test.
Where should I install carbon monoxide detection devices? What is proper carbon monoxide detection device placement?
It is very important to install carbon monoxide detection device near or in each sleeping area. Many states now require that a carbon monoxide detection device is placed in each bedroom. For added protection, placement of an additional carbon monoxide device at least 15-20 feet away from the furnace or fuel burning heat sources is recommended. Also, install carbon monoxide detection devices at least 10 feet from sources of humidity like bathrooms and showers. In two story houses, install one on each level of the home. If you have a basement, carbon monoxide CO detection device placement is recommended at the top of the basement stairs.
Is there anywhere I shouldn’t install carbon monoxide detection devices?
Do not install carbon monoxide detection devices in any extremely dusty, dirty, humid, or greasy areas. Do not install detection devices in direct sunlight, or areas subjected to temperature extremes. Do not install in unconditioned crawl spaces, unfinished attics, uninsulated or poorly insulated ceilings, and porches unless listed for use in these areas. Carbon should not be installed in outlets covered by curtains or other obstructions. Do not install in turbulent air near ceiling fans, heat vents, air conditioners, fresh air returns, or open windows. Blowing air may prevent carbon monoxide from reaching the CO sensors.
Is it a carbon monoxide false alarm when my CO alarm sounds when there doesn’t seem to be a problem?
Carbon monoxide false alarms should not occur if your alarm is in working order. Remember, CO is an odorless, colorless gas. If your CO detection device went off, it detected potentially harmful amounts of CO. After the professionals have evaluated the situation, make sure no one has any symptoms of CO poisoning. Here are a few situations that may cause false alarms:
- The CO alarm needs to be relocated. CO detection devices should be located 15 away from all fossil fuel burning sources like furnaces and stoves. Alarms should be located 10 feet away from sources of humidity like showers.
- Fossil fuel burning appliances may not be burning fuel completely. Check pilot lights/flames for blue color. Appearance of yellow or orange flames indicates incomplete combustion source of carbon monoxide.
How many carbon monoxide detection devices should I have in my home?
So how many carbon monoxide detection device detection devices should you have in your home? The National Fire Protection Association (NFPA) recommends that you should have a carbon monoxide device centrally located outside of each separate sleeping area in the detection device immediate vicinity of the bedroom. For added protection, you should have additional carbon monoxide detection devices in each separate bedroom and on every level of your house, including the basement. Some states now require that you have a carbon monoxide detection device in each bedroom of the house. If you install only one in your home, locate it near or in your bedroom.
I wonder where to install carbon monoxide alarms, particularly how high off the floor?
Carbon monoxide weighs about the same as air and distributes evenly throughout the room/house. When you decide where to install a carbon monoxide alarm, choose a location where the CO alarm will stay clean and out of the way of children or pets. It is important to refer to your user’s manual for specific installation requirements as to where to install your carbon monoxide alarm.
Why does the red light flash on my carbon monoxide alarm? Do I have CO?
On many carbon monoxide alarms receiving battery power, the red light flashes to show the CO alarm is properly For these alarms, when you do not see the red light flashing, replace the batteries in the alarm immediately.
Can you reset a plugin CO alarm with the test silence button?
No, the test silence button only tests or silences the CO alarm. To reset the alarm, the unit needs fresh air and time to clear the device.
Can I unplug the CO alarm to silence or reset it, or do I need to leave it plugged in?
Many plugin carbon monoxide alarms will only reset when they are receiving electricity. Press and hold the Test/Silence button for 5 seconds to quiet they are a plugin alarm while ventilating. You may have to do this numerous times to give the alarm time to reset.
What is the proper way to do a carbon monoxide alarm test?
The proper way to do a carbon monoxide alarm test is to press and hold the test button until the alarm sounds. Be sure you hold the button down long enough. It can take up to 20 seconds for the alarm to respond to your test.
Can I do a CO alarm test in any other way besides pressing the test button?
Pressing the test button is the only proper way to test the CO alarm. NEVER use vehicle exhaust or some other source of combustion fumes. Exhaust causes permanent damage and voids your warranty.
Can I remove the battery from the CO alarm to silence or reset it?
Do not remove the battery from your CO alarm to silence or reset it. The CO alarm is designed to reset automatically. Use the Test/Silence Button to quiet the alarm while the alarm is resetting. Leave the battery in your CO alarm.
My battery powered CO alarm keeps chirping. Tell me how to get a carbon monoxide alarm to stop chirping.
If your CO alarm keeps chirping, the battery may be low or weak. Consult your owner’s manual on how to determine whether the battery is low. The way to get a carbon monoxide alarm to stop chirping is to replace the battery.
Why should I leave the carbon monoxide (CO) alarm plugged in all year?
Leave your carbon monoxide alarms plugged in all year. Carbon monoxide gas problems can happen at any time. Remember your furnace or space heaters aren’t the only sources of carbon monoxide. Portable generators, gas ranges, water heaters, dryers, charcoal grills, gas powered tools or vehicles left running in an attached garage can all cause carbon monoxide problems.
Do carbon monoxide alarms and detectors have an audible alarm signal?
All carbon monoxide alarms and detectors are required to produce an 85-decibel audible alarm sound when carbon monoxide reaches the alarm level.
What is the expected carbon monoxide alarm battery life?
Actual carbon monoxide detection device alarm battery life depends on the specific carbon monoxide detection device and the environment in which it is installed. Batteries specified in the manual are the only acceptable replacement batteries. Regardless of the manufacturer’s suggested carbon monoxide alarm user’s battery life, you MUST replace the battery immediately if the unit starts “chirping” to signal the end of its battery life.
What are the key differences between carbon monoxide alarms and carbon monoxide detectors?
Most carbon monoxide alarms and detectors available on the market are listed by an independent, nationally recognized testing laboratory (NRTL) accredited by the U.S.
Occupational Safety and Health Administration (OSHA) to comply with one of the two product standards published by Underwriters Laboratories Inc. (UL). Such standards are developed according to the standards development guidelines adopted by the American National Standards Institute (ANSI).
Carbon monoxide alarms can be single- or multiple-station units that detect carbon monoxide and are either hardwired into the building’s AC power, operated by a battery, or plugged into an electrical outlet (generally with battery backup). Single-station alarms are detectors that incorporate a sensor, control components, and an alarm notification appliance in one unit operated from a power source either located in the unit or obtained at the point of installation.
Multiple-station CO alarms are single-station alarms capable of being interconnected to one or more additional alarms so that the actuation of one causes the appropriate alarm signal to operate in all interconnected alarms. All such alarms are listed for compliance with ANSI/UL 2034 Standard for Single- and Multiple-Station Carbon Monoxide Alarms. Alarms that combine carbon monoxide and smoke detection in a single unit are also available.
Carbon monoxide detectors are devices connected to an alarm control unit having a sensor that responds to carbon monoxide. These system-connected carbon monoxide detectors and sensors generally are listed for compliance with ANSI/UL 2075 Standard for Gas and Vapor
Detectors and Sensors.
In general, single- or multiple-station carbon monoxide alarms
- are lower in cost per unit than CO detectors;
- do not have the capability of sending an alert to a remote supervising station or constantly attended onsite location, instead relying on individuals to hear and respond to alarms;
- must be replaced when the device reaches end of life (typical life of sensor); and
- could be used as an alternative to CO detectors in existing construction in an effort to control costs.
In general, system-connected carbon monoxide detectors
- transmit signals to an approved remote supervising station or constantly attended onsite location, allowing for timely notification and response to CO incidents;
- can be operated as a stand-alone system or combined with either a new or existing fire alarm system or security system;
- should be required in new construction;
- are higher in cost per unit than CO alarms; and
- must be replaced when the device has reached its end-of-life (typical life of sensor).
For new construction in commercial occupancies, system-connected carbon monoxide detectors should be required, as the cost is minimal when included in the initial planning and estimates. CO detection can be incorporated with other life safety systems.
For existing construction in commercial occupancies, system-connected CO detectors are preferable for the advantage they offer in being able to send alerts to constantly attended onsite locations or approved remote supervising stations. However, acknowledging budgetary constraints and the need to control costs, single- or multiple-station alarms may be considered as an alternative, provided someone will be in a position to hear and/or respond to them should they signal.