Jack Pixley's Homeowner's Guide

What every homeowner should know about carbon monoxide

Carbon monoxide (CO) is an odorless, colorless, tasteless gas which is very toxic. Exposures to CO can cause symptoms such as headaches, dizziness, weakness, nausea, vomiting, or loss of muscle control. However, there could be many other causes for these symptoms and that is why carbon monoxide poisoning is so difficult to diagnose. If inhaled, carbon monoxide crowds out life-sustaining oxygen from red blood cells. Prolonged exposure to high concentrations of CO can lead to unconsciousness, brain damage, or death.

Gasoline-powered vehicles and lawn mowers, kerosene stoves, charcoal grills, coal stoves or heaters, and wood burned in fireplaces or woodstoves produce some carbon monoxide. Tobacco smoke also contributes CO to the air you breathe but only in very small amounts.

When properly installed and maintained, your natural gas furnace and hot water heater do not pollute your air space with carbon monoxide. The main ingredient of marketed natural gas is methane, which is not poisonous. Natural gas is known as a "clean-burning" fuel because under correct operating conditions the combustion products are water vapor and carbon dioxide, which do not damage the environment. [Carbon dioxide (CO2) is also present in the air we exhale and is necessary for plant life.] The products of combustion are exhausted from furnaces and water heaters to the outside by means of a flue vent or chimney.

  • An adequate supply of air for complete combustion
  • Venting of the products of combustion from the furnace through the chimney or vent to the outside

THREE CAUSES OF HAZARDOUS CONDITIONS AND HOW TO PREVENT THEM

1. Dirt and Blockage

  • Never insulate or try to seal up a draft hood, wind cap or exhaust vent on any gas appliance (furnace, hot water heater, range, dryer or space heater). Keep your equipment area clean.

  • Don't store anything that could restrict air circulation close to equipment.

  • It is absolutely essential to your safety that panels and grilles on the furnace be kept in place and that the fan compartment door is closed when the furnace is operating.

  • If you have a gas water heater, make sure that combustion air openings at the bottom of the tank and the opening below the draft diverter (on top of the tank next to the flue duct) remain unblocked.

  • If you have a gas dryer, the exhaust duct must be vented to the outside and have a hood at the end. Check that the exhaust system is not blocked by lint or debris and that the flapper in the hood moves freely.

  • For all fuel-burning equipment, make sure that vent hoods and pipes are not blocked by insulation, leaves or bird nests.

2. Using Other Equipment that Consumes or Exhausts Household Air

  • If you use exhaust fans and a fireplace or other fuel-burning heater or stove.

  • Run exhaust fans for just a minute or two at a time prolonged use could remove too much air and also wastes heat.

  • Don't run power attic vents during the winter or when your furnace is on.

  • When your fireplace, coal or woodstove is operating, open a window and close off warm air registers in the room, or install a fresh air duct for the fireplace or stove so that your home has adequate make-up air.

3. Confining or Enclosing Gas-Fired Equipment

If you've partitioned off your furnace and water heater, you may need additional ventilation.

DANGER SIGNS

Stuffy, stale or smelly air, backdrafts and soot from a fireplace or furnace chimney usually mean your home needs more air for proper combustion and healthy living. For gas- fired equipment, mostly yellow (rather than clear blue) burner flames, a pilot light that keeps going out, or an odor of gas indicate trouble. Turn off the equipment and contact your gas company emergency service.

ADDITIONAL SAFETY TIPS

Have your fuel-burning equipment checked periodically for safety and efficiency by a qualified service technician.

If you're adding a wood or coal burning stove to a home, make sure that the stove is properly installed and vented. Check with the Building Inspections Department of your local municipality or consult a licensed contractor before installation. If you've already installed a wood or coal stove without a building permit or inspection, consult your local municipal building authority. Some "do-it-yourselfers" have unknowingly created dangerous conditions. Once you file for a permit, a qualified inspector will check your installation and explain how to rectify any mistakes.

Don't expose yourself to carbon monoxide through carelessness. Never operate a gasoline-powered engine in a confined or enclosed space such as a garage or tool shed. Never use a kerosene stove or charcoal grill in a confined space such as a closed garage or recreational van.

If you have a forced warm-air furnace, make sure that there is no cold air return register in a small enclosed furnace room.

On masonry chimneys, inspect the clean-out regularly to ensure that the chimney is free and clear of debris. . Regardless of the fuel your furnace, fireplace or stove uses, your chimney should be inspected from time to time by a CSIA certified chimney technician.

Never try to add a "heat reclaimer" or "automatic flue damper" to your gas furnace or water heater. Gas installation safety codes prohibit use of these devices as an add-on to an existing furnace because of the risks of incorrect installation and mechanical failure.

Following sensible maintenance and safety procedures in the home will give you fuel savings without endangering your health.