Smoke Alarms

How do I know if my home requires additional smoke or carbon monoxide alarms?

The required number of smoke alarms or carbon monoxide alarms by Building Regulation may not provide early warning and protection in areas of your home where a door separates protected areas from unprotected areas.
Battery only alarms will not meet the requirements of Building Control for New Build/Refurbishments etc; these must be hard wired alarms.
For this reason, it is recommended that the household consider the use of additional smoke alarms and carbon monoxide alarms in these areas for increased protection. The additional areas may include a basement, bedrooms, dining room, utility room, and hallways. We recommend at least one carbon monoxide alarm on each level of your home.

Where should I locate my smoke alarm in the home?

Smoke alarms should be mounted in or near bedrooms and living areas, either on the ceiling or the wall. Ceiling mounting it is typically preferred as it allows the smoke alarm to be placed more centrally in the room. If wall mounting is used it is best to use an inside wall to avoid thermal air currents that can occur along hot or cold walls. Our units have been tested and will perform between 40 degrees and 95 degrees Fahrenheit.

How should I dispose of my old smoke alarm?

Typically, smoke alarms should not be disposed of with your regular domestic waste. They should be disposed of in accordance with WEEE regulations.
Single alarms can be disposed of in the household waste stream if your local recycling has no special smoke alarm arrangements, but ideally they should be taken to your local recycling facility and disposed of alongside other small electrical equipment.

How many smoke alarms should I have in my home?

Kidde recommends a minimum of one smoke alarm per floor, and one per bedroom or sleeping area, so for a typical 3-bedroom home on two levels we would recommend at least 5 working smoke alarms. Alarms can be sensitive to cooking smoke and heat from a kitchen and steam from a bathroom. Consider installing alarms away from these rooms if possible to avoid potential nuisance alarms.

How can I tell if my smoke alarm is working?

The smoke alarm should be operating once AC power is applied, fresh batteries are installed and testing is complete.
Testing procedures:
You can test your smoke alarm by pushing the Test/Hush button on the cover and holding it down for a minimum of 5 seconds. This will sound the alarm if the electronic circuitry, horn and battery are working. In an interconnected installation all interconnected alarms should sound when the test feature on any one of the interconnected alarms is activated. If no alarm sounds, check the fuse or circuit breaker supplying power to the alarm circuit. If the alarm still does not sound, the unit may have defective batteries or another failure.
DO NOT use an open flame to test your smoke alarm, you could damage your alarm or ignite combustible materials and start a structure fire. Test your smoke alarms weekly to ensure proper operation. Erratic or low sound coming from your smoke alarm may indicate a defective alarm, and should be returned for service (refer to your warranty).

How often should I replace my smoke alarm?

Kidde recommends replacing your smoke alarms every 10 years, and carbon monoxide alarms every 7 years. If you don't know how old your alarm is, look for the manufacturing date code on the back of the alarm(s) or simply replace them to avoid any danger.

What is the difference between ionisation and photo-electric (optical) smoke alarm technologies?

There are two types of smoke alarm technologies currently available to homeowners: ionization and photoelectric. These technologies are sold in either single-station ionization or photoelectric smoke alarms, or in a dual-sensor smoke alarm that combines both technologies into one unit.
Ionization smoke alarms sound when electrically charged ("ionized") particles released in a fire interfere with the electrical current that flows through the alarm's detection chamber. The disruption in the current causes the smoke alarm to sound.
Photoelectric smoke alarms sound when smoke particles interfere with, and reflect the alarm's light beam that travels through the alarm's detection chamber, thereby triggering the alarm.
Because of these different detection technologies, ionization sensors are more likely to detect smaller, less visible fire particles, like those produced by flaming fires, sooner than photoelectric sensors. However, photoelectric sensors are more likely to detect larger, more visible fire particles, such as those produced by smouldering fires, sooner than ionization sensors

Why does my smoke alarm beep or chirp?

Several things could be causing your alarm(s) to alarm briefly or "chirp" randomly without a regular pattern.
First, you should verify how your alarm is chirping or sounding:
Consistently at regular time intervals (see consistent chirping) or randomly without a regular pattern (see below)
If the unit chirps at seemingly random times or at random intervals (after replacing the battery) check for the following conditions:
The battery may be loose, or improperly installed.
Verify that a battery of the recommended type is securely installed. Make sure to use a battery with a use-by date no later than four to five years in the future. Check that the battery is snapped in completely so it cannot be shaken loose. It's possible that battery connections may not be making good contact with the battery. Disconnecting and re-connecting the battery once or twice will likely fix this condition. On units with a front-load battery, be sure that the battery compartment door is closed completely as well. Loose white neutral wire can cause an echoing chirp. (From one unit to the next)
The smoke alarm sensing chamber may be dirty.
Dust and insects can collect in the sensing chamber of the alarm. An accumulation of dust in the sensing chamber can cause the unit to chirp. It is good practice to clean the smoke alarm when you change the battery. Static electricity from the ac quick connector attracts dust and can cause false alarms.
Cleaning smoke alarms:
To clean your alarm, remove it from the mounting bracket as outlined here. You can clean the interior of your alarm (sensing chamber) by using compressed air or a vacuum cleaner hose and blowing or vacuuming through the openings around the perimeter of the alarm. The outside of the alarm can be wiped with a damp cloth. After cleaning, reinstall your alarm, verify the green LED is on and test your alarm by using the Test Button. If cleaning does not restore the alarm to normal operation, the alarm should be replaced.
Check environmental conditions:
Humidity, steam and condensation can cause false alarms. Causes of condensation are:
- Extreme temperatures changes.
- High ambient humidity.


Reset the alarm.
Some current model smoke alarms have a processor that retains certain error conditions, such as a weak battery. The error condition should reset when the battery is replaced but sometimes it does not and must be manually reset to clear the error.
To reset an AC unit with a battery backup:
Turn off the power to the smoke alarm at the circuit breaker. Remove the smoke alarm from the mounting bracket and disconnect the power. Remove the battery. Press and hold the test button for at least 15 seconds. The unit may chirp or alarm for a few seconds before going silent. Reconnect the power and reinstall the battery. The unit will chirp once when the power is restored and should not chirp afterwards.
To reset a battery-only unit:
Remove the battery. Press and hold the test button for at least 15 seconds. The unit may chirp or alarm for a few seconds before going silent. Reinstall the battery. The unit will chirp when the battery is first connected but should not chirp afterwards.
An electrical condition may be causing the power to the unit to be interrupted.
If the AC power to the unit is interrupted, the unit will chirp when the power is restored. This could be caused by power surges. If the chirping seems to occur at about the same time in the evening or morning, it could be due to a surge created when the power company switches electrical grids to meet demand. Check to see if the chirp (or chirping) occurs when something else in the house is turned on such as an exhaust or attic fan, a heater, etc. If the smoke alarm is connected to a circuit with such a device, the alarm may chirp when the other device is switched on. If this is the case and the device is plugged into a wall outlet, move it to another outlet on a different circuit. If it is a hardwired device, have an electrician investigate it. These conditions can be minimized by installing your alarms on a dedicated circuit in compliance with NFPA requirements.
Replace the alarm.
If none of these conditions exist and the suggestions don't alleviate the symptom, the alarm should be replaced. Age may be a factor. Smoke and heat alarms should be replaced every 10 years, and carbon monoxide and combination alarms should be replaced every 7 years. Most of our alarms have a 5 year warranty from date of purchase (check your user manual for details). A date code is stamped on the label attached to the back of the unit.
If the unit is out of warranty, please purchase a replacement product immediately.
If the unit is within warranty, please contact Kidde Safety on 0800 917 0722

What type of replacement battery should I buy for my smoke alarm?

We recommend you always refer to the product label found on the back of your alarm, or the user's manual, to identify which type, brand and battery model is recommended for your specific alarm. Alarms require fresh and powerful batteries and sometimes off-brand batteries, or those that have been sitting on the shelf for several years, will not be powerful enough and may cause your alarm to go into low-battery mode.

What should I do if my smoke alarm sounds?

When the alarm senses products of combustion and goes into alarm mode, the pulsating alarm will continue until the air is cleared. If your unit is in Full Alarm and there is no presence of smoke, check our Solution Finder to see Intermittent Chirping solutions.
What to do when the alarm sounds:
Alert small children in the home.
Leave immediately by your escape plan. Every second counts, so don't waste time getting dressed or picking up valuables.
In leaving, don't open any inside door without first feeling its surface. If hot, or if you see smoke seeping through cracks, don't open that door! Instead, use your alternate exit. If the inside of the door is cool, place your shoulder against it, open it slightly and be ready to slam it shut if heat and smoke rush in.
Stay close to the floor if the air is smoky. Breathe shallowly through a cloth, wet if possible.
Once outside, go to your selected meeting place and make sure everyone is there.
Call the fire department from your neighbour's home - not from yours!
Don't return to your home until the fire officials say that it is all right to do so.
IMPORTANT: Never Ignore the Sound of an Alarm!

How should I test that my smoke alarm is working properly?

Using the test button will ensure an accurate and complete test that your alarm(s) are working properly. When testing interconnected units be sure to verify all the alarms in the system sound.
Aerosol products can be used to test a smoke alarm. If using this method be sure the follow the instructions supplied by the manufacturer of the aerosol, and direct the spray so it enters the alarm sensor area. The holes on the cover of the alarm are for the sound to emit. If the spray is aimed directly at this area it will not enter the sensing chamber area. Smoke entry in an alarm is through the opening around the perimeter.
Hold the aerosol about 2 feet away from the alarm. Make sure the can is parallel to the wall or ceiling, depending on where your smoke alarm is mounted. This will allow the test spray to travel along the wall or ceiling and enter the openings on the perimeter of the alarm.
NOTE: Excessive spraying at close range may permanently affect the smoke alarm's sensitivity.
NOTE: Igniting combustible materials to test your alarm is not recommended. An accident could occur and result in a fire.

Why does my smoke alarm sometimes go off in cold conditions?

Your smoke alarm may sound when its very cold outside, or if a door adjacent to a heated area is opened, like in an entryway. This is due to condensation (water vapor) in the detection chamber. The sensor is a particle sensing device, when water condenses in the sensor the unit will go into alarm. The operating temperature of a smoke alarm is between 40 and 100 degrees Fahrenheit (4.4ºC - 37.8ºC). If the unit is in a garage or attic, you should consider replacing it with a heat alarm which is not affected by condensation.

Will extreme temperatures affect my smoke alarm?

Our smoke, carbon monoxide and combination alarms have been tested and will perform between 40 degrees and 100 degrees Fahrenheit (4.4ºC - 37.8ºC). Reasonable exposure within these temperatures will not cause permanent damage. We do not recommend operating these alarms at, or outside these limits.

The test button of my smoke alarm does not seem to work

Check that it is being held down for at least 2 - 3 seconds, after which the alarm should sound.

Cigarette smoke (blown at alarm) is not setting off the alarm - is it faulty?