How to Buy Carbon Monoxide Detectors

Called "the silent killer," odorless, tasteless carbon monoxide (CO) gas results from faulty combustion in a furnace, fireplace or gas range, or a car (in an garage). A CO detector is your only means of protection.

Difficulty: Easy

Instructions

1. Shop for a CO detector. There are only three types; they're all affordable ($30 to $50) and easy to install:

2. A biometric CO detector has a gel cell of synthetic hemoglobin that absorbs CO. The combination battery and sensor module must be replaced every two to three years, but the detector should last about 10 years. After an alarm, the sensor should clear itself within 2 to 48 hours when left in fresh air. If it is not cleared, it will sound again when put back in the detector. Sensors that don't clear must be replaced.

3. A semiconductor detector is a plug-in device with an electronic sensor, and lasts from 5 to 10 years.

4. An electrochemical detector responds differently to different levels of CO exposure. Its self-powered battery doesn't need to be replaced, and the detector will last for at least five years.

5. Look for the Peak CO Memory feature on higher-end models. These displays remember the highest level of CO registered over a given time, which helps emergency personnel determine the severity of the problem, and can tell you if the detector sensed high CO levels while you were away.

6. Buy a detector with special light features if someone in your family is hard of hearing. During an alarm, an indicator light flashes as the horn sounds. Although many alarms have a liquid crystal display (LCD), it's easier to read a light-emitting diode (LED) display in dim light.

7. Listen for a continuous siren that indicates a full alarm. A repetition of loud pulsating beeps means there is some CO buildup; a chirp every minute alerts you to an alarm or battery problem.

Tips & Warnings

• Whichever type of alarm you choose, buy the freshest one available. Open the package to find the date of manufacture stamped on the back.
• Look for Underwriters Laboratories (UL.com) certification.
• Many building codes now require CO detectors if a house is heated by gas or oil or has a fireplace.

[djcrane]

on 1/18/2007 1. The first type of alarm is "biomemetic", not biometric.
2. One type electrochemical alarm actually tests itself to be sure the sensor can still detect gas; others may signal when the device has been in service (power applied) for about 5 years. Electrochemical alarms can last more than 5 years - but you need that self-test feature.
- CO capability comes in combination alarms (with smoke). The CPSC recommends replacing smoke alarms after 10 years. A combo smoke / CO is a good replacement and upgrade option in that situation.

on 11/22/2005 If the power goes out, be sure your detector has a battery back-up. Also, learn to distinguish between the sound of your smoke and CO alarms.