Skip to main content
Frequently Asked Questions
Carbon Monoxide Alarm FAQs
Carbon monoxide is a colourless, tasteless and odourless gas that is produced when fossil fuels such as coal, oil, natural gas, LPG, charcoal and wood are not burned efficiently.
It can be produced from poorly maintained or badly fitted domestic heating appliances such as boilers, wall heaters, wood burners, blocked flues or exhaust vents.
  • Your alarm will indicate end of life seven or ten years after initial power. It will 'chirp' every 30 seconds. The chirp will not stop until the unit is powered off. You'll know that it is an end-of-life warning and not a low battery warning because replacing the batteries will not stop the chirp.
  • The chirp will stop only when the alarm is powered off.
  • Note. The alarm will not detect the presence of CO when in this mode. Replace the CO alarm with a new one immediately.
The symptoms of CO poisoning include headaches, sickness, tiredness and muscle pain - all of which can easily be misdiagnosed as flu.
Because carbon monoxide (CO) is a cumulative poison; two factors determine how CO affects your body. The first one is the amount of CO present and the second is the length of exposure. Your alarm is designed to react as the human body does to CO. A high level of CO will cause an alarm very quickly while a lower level may take hours.
This is a low battery signal.
An ERR message indicates an alarm malfunction. It will alert you with a short "chirp" and the red LED will flash once every 30 seconds. Push the Test/Reset button; hold it for 5 seconds, then release. If the reset is successful, the display will reset to zero. If it's an actual malfunction, the unit will go back to ERR within 5 minutes. The alarm should be replaced.
A digital display allows you to see if carbon monoxide is present and respond before it becomes a dangerous situation. Peak Level Memory stores the highest recorded reading prior to being reset. This feature enables you to know if there was a reading while you were away from home, and can also help emergency responders determine the best treatment.

Any time you push the Test/Reset button the alarm will test the electronics are functioning correctly. The LCD will display 3 bars followed by 888 and return to 0.

The Peak Level reading is just a memory. At one point the unit was exposed to something the caused the reading. It could have been a substance that was sprayed too close to the unit, paint fumes, or actual carbon monoxide that caused the reading. To reset the peak level, push the Peak Level button, and hold it down while you press and hold the Test/Reset button for 2 seconds, then release them at the same time. After this, monitor the unit for a few days to determine if this is a recurring problem or if it was an old reading. If you don't get a reading, then you know it could have just been a random reading and you have no other event taking place. If a reading does return, reset the peak level again and start watching it every 1-2 hours, and try to narrow down when the reading is happening and be aware of what's going on around you (heat coming on or off, cleaning etc.) to determine the source of the reading.

When the CO alarm emits a quick beep every 30 seconds and the red LED flashes, you may need to change the batteries. Once you have replaced the batteries, if the alarm continues to emits a quick beep every 30 seconds and the red LED flashes, the alarm has reached the end-of-life. When an alarm has reached the end of its life, it needs to be replaced to continue protecting your home.
  • The battery may be loose or improperly installed. Verify that battery of the recommended type is securely installed.
  • The battery may be low and require renewing.
  • The alarm may be malfunctioning.
  • The alarm may have reached the end of its life.
Kidde carbon monoxide and combination alarms should be replaced every 7/10 years ( depending on the model ) and they all have an end of life warning that will sound continuously when it is time to replace the alarm. If you don't know how old your alarm is, look for the manufacturing date code on the back or side of the alarm(s).
While pressing the Peak Level Memory button, press the Test/Reset button for two seconds and release both at the same time. The number on the display will turn to 0, the memory will be cleared and the carbon monoxide (CO) alarm will begin monitoring for CO. The Peak Level Memory will also reset when the unit loses power.

Carbon monoxide (CO) and combination alarms should be mounted in or near bedrooms and living areas, no closer than 20cm from the ceiling. If mounting on a ceiling please make sure it is at least 20cm away from the wall. Because carbon monoxide is almost the same density as air, it will disperse evenly throughout the air in a room.

We recommend you install a carbon monoxide or combination alarm on each level of a multi-level home. If your home has only one CO or combination alarm, it should be installed in the main bedroom or in the hallway outside of the sleeping areas. Place the alarm at least 1.5m away from fuel-burning appliances. Make sure nothing is covering or obstructing the unit. Do not place the unit in dead air spaces or next to a window or door.

CAUTION: Carbon Monoxide alarms will only indicate the presence of carbon monoxide at the sensor. Carbon monoxide may be present in other areas of your home.

This is normal. The amber, green & red LED come on when you press the test button to show that they operate correctly. You should consult the user guide if the amber LED comes on at any other time.
No - this is very dangerous and not reliable. Pressing and holding the test button is a sufficient means of testing that the alarm is fully operational.
Our carbon monoxide (CO) alarms are designed to act as a continuous monitor. You should install your alarm and leave it in one place.

Call 112 or your local gas emergency service immediately and move to fresh air. Either go outdoors or go near open doors or windows. Do a head count to check that all persons are accounted for. Do not re-enter the premises nor move away from an open door/window until emergency service responders have arrived, the premises have been aired out, and your alarm is in its normal condition. If your alarm reactivates within a 24 hour period, repeat steps 1-3 and call a qualified appliance technician to investigate for sources of carbon monoxide (CO) from fuel burning equipment and appliances, and inspect for proper operation of this equipment. Any problems identified should be corrected immediately. Make sure that motor vehicles are not, and have not been, operating in an attached garage or adjacent to the residence.

IMPORTANT: Never Ignore the Sound of an Alarm!

WARNING! Activation of your CO alarm indicates the presence of Carbon Monoxide which can KILL YOU.

Kidde recommends replacing your carbon monoxide alarms every 7/10 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.