Kidde 10-year digital CO alarm review

What it is and who it suits

Kidde's user guide covers six battery-powered CO alarms. The digital models with a sealed 10-year battery are the COBD10 and the COBDL10. The COBDL10 adds a low-level CO alert, and the COBD10 does not, so check the model letters on the box, because the listing we track does not name one. This review follows the guide, and Kidde's COBD10 page is the closest match we found.

It suits a home that wants an alarm that keeps working through a power outage and that shows a number. CDC says to install battery-operated or battery back-up CO detectors near every sleeping area and suggests a detector with a digital readout. This review is researched, not tested. It relies on Kidde's page and user guide, CDC and Ready.gov.

Battery, life and warranty

Kidde says the battery is a sealed 10-year lithium unit that cannot be replaced and never needs changing, and that activating it is a one-time operation that cannot be turned off afterward. The guide says the alarm will alert you to replace it ten years after it was powered up, and tells you to write a replace-by date on the label before you install it. Kidde's page lists a 10-year limited warranty, and notes that constant exposure to high or low temperatures or high humidity may reduce battery life.

The guide says that when the low battery warning starts, a sealed-battery unit must be replaced within 7 days to keep continuous detection. The guide also says the National Fire Protection Association and the manufacturer recommend replacing the alarm after ten years. CDC's guidance is to replace a detector following the manufacturer's instructions or every 5 years. Follow the label date and do not stretch it.

Display, alarm and memory

In a CO alarm the guide says the pattern is four quick beeps repeating every 5 seconds, with a red light blinking in time and the display alternating between the ppm reading and CO. After 4 minutes the pattern repeats only every 60 seconds. The guide lists alarm times: at 70 ppm it sounds in 60 to 240 minutes, at 150 ppm in 10 to 50 minutes, and at 400 ppm in 4 to 15 minutes. It says these models have not been investigated for alarming below 70 ppm.

A peak-level button shows the highest CO reading the unit has recorded, which the guide says appears from 31 to 999 ppm, and the unit keeps an alarm memory for 7 days. The guide describes readings of 31 to 50 ppm as low and 50 to 100 ppm as a cause for concern, and says that any time someone has symptoms of CO poisoning, it should be treated as an emergency. The alarm is rated 85 decibels or more at 10 feet, and the sensor is electrochemical.

What to do when it sounds

Kidde's guide says to evacuate everyone to fresh air at once and call 911 or the fire department, and to treat the alarm as dangerous. It says to have an appliance technician inspect fuel-burning equipment once the home has been aired out and the alarm is back to normal, and to check that no vehicle has run in an attached garage. CDC lists headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion as the most common symptoms, and our carbon monoxide poisoning guide covers the rest.

Where to put it and what it is not for

Kidde's guide says industry experts recommend an alarm on each level of the home, ideally any level with fuel burning appliances and outside sleeping areas, and not in the garage or within 6 feet of heating or cooking appliances. Ready.gov says to install detectors with battery backup in central locations on every level. The guide lists an operating range of 40 to 100°F. It says the models are not designed for an RV or boat, and says to test the alarm weekly with the Test/Hush button.

Who should skip it

Skip it if you want a single device for both smoke and CO, which is a different product, or if you want the low-level alert, which only the L models have. Skip it for an RV or boat. Our carbon monoxide alarm comparison lists the alternatives, and the power outage checklist shows where an alarm fits in the wider plan.

How long does the battery in the Kidde 10-year CO alarm last?

Kidde says the sealed lithium battery lasts ten years and cannot be replaced, and the alarm tells you to replace the unit ten years after power-up. High or low temperatures and high humidity may shorten battery life.

What does the display show?

The display shows the CO level in ppm, and in an alarm it alternates between the ppm reading and CO. A peak-level button shows the highest reading, from 31 to 999 ppm, per Kidde's guide.

What should I do when it alarms?

Kidde's guide says to get everyone outside to fresh air and call 911 or the fire department. Once responders have arrived and the home has been aired out, have a qualified technician inspect fuel-burning appliances.

How often should I replace a CO alarm?

Kidde says ten years, and the alarm signals end of life. CDC says to follow the manufacturer's instructions or replace the detector every 5 years. Use the label date and do not run past it.