Use and Care Manual

14. General Carbon Monoxide (CO) Information

Carbon monoxide (CO) is a colorless, odorless, and tasteless poison gas that can be fatal when inhaled.

CO inhibits the blood’s capacity to carry oxygen.

Possible Sources of CO

Inside your home, appliances used for heating and cooking are the most likely sources of CO. Vehicles

running in attached garages can also produce dangerous levels of CO. CO can be produced when

burning any fossil fuel: gasoline, diesel, propane, natural gas, oil and wood. It can be produced by any

fuel-burning appliance that is malfunctioning, improperly installed, or not ventilated correctly, such

as: Furnaces/boilers, gas ranges/stoves, gas clothes dryers, water heaters, portable fuel burning space

heaters, fireplaces, wood-burning stoves and certain swimming pool heaters. Blocked chimneys or flues,

back drafting and changes in air pressure, corroded or disconnected vent pipes, or a loose or cracked

furnace heat exchanger can also release CO into your building. Vehicles and other combustion engines

running in an attached garage and using a charcoal/gas grill or hibachi in an enclosed area are all possi-

ble sources of CO.

The following conditions can result in transient CO situations:

Excessive spillage or reverse venting of fuel-burning appliances caused by outdoor ambient conditions

such as: Wind direction and/or velocity, including high gusts of wind, heavy air in the vent pipes (cold/

humid air with extended periods between cycles), negative pressure differential resulting from the

use of exhaust fans, simultaneous operation of several fuel-burning appliances competing for limited

internal air, vent pipe connections vibrating loose from clothes dryers, furnaces/boilers, or water heaters,

obstructions in, or unconventional, vent pipe designs which can amplify the above situations, extended

operation of unvented fuel-burning devices (range, oven, fireplace, etc.), temperature inversions which

can trap exhaust gases near the ground, car idling in an open or closed attached garage, or near a

home.

CO Safety Tips

Every year, have the heating system, vents, chimney and flue inspected and cleaned by a qualified

technician. Always install appliances according to manufacturer’s instructions and adhere to local

building codes. Most appliances should be installed by professionals and inspected after installation.

Regularly examine vents and chimneys for improper connections, visible rust, or stains, and check for

cracks in furnace heat exchangers. Verify that the color of flame is blue on pilot lights and burners. An

amber or orange flame is a sign that the fuel is not burning completely and may be releasing CO. Teach

all household members what the alarm sounds like and how to respond. Fire Departments, most utility

companies and HVAC contractors will perform CO inspections. Some contractors may charge for this