One of the ways to prevent combustion spillage in your home is to have a professional make sure that your chimney is not cracked, and that it is clear of obstacles such as pieces of broken bricks, ice or dead birds. Blocked chimneys can force combustion gases back into your home, instead of outside where they belong.

Most fuel-burning devices are designed to vent the gases they produce to the outdoors. But unfortunately, combustion systems don't always work the way they are supposed to.

If your home has a wood stove, fireplace, or an oil- or gas-fired furnace, boiler or water heater, be aware that under certain conditions combustion gases could be spilling into your home. Left unchecked, these toxic gases could lead to potentially serious health problems, ranging from headaches and minor illnesses to carbon monoxide poisoning or even death.

 To keep combustion gases out of your home:

• Start an annual maintenance and cleaning schedule for all of your combustion appliances. This includes hiring a professional to check for heat exchanger leakage (a heat exchanger is a device that is built to transfer heat from one medium to another, such as a radiator in a car); looking for evidence of start-up spillage or condensation in chimneys; and carrying out a thorough tune-up of any combustion devices in your home.
• Have your chimney inspected on an annual or bi-annual basis. Blocked chimneys can force combustion gases back into your home, instead of outside where they belong. Have a professional make sure that your chimney is not cracked, and that it is clear of obstacles such as pieces of broken bricks, ice or dead birds.
• If you are building a new home or renovating your existing one, consider upgrading your chimney or investing in appliances that are less prone to spillage. Try to minimize the backdrafting of gases into your home by not operating multiple exhaust devices (range hoods, clothes dryers, bathroom fans, central vacuums) at the same time, and by making sure that air can move freely between your furnace room and the rest of the house. When in doubt, get expert advice on how to install, operate and maintain your combustion appliances.
• If you have an open fireplace, always keep your chimney well maintained, be sure to provide extra air from outdoors whenever a fire is lit, and keep the fireplace doors tightly shut when a fire is burning or smouldering. You may also want to consider installing an energy-efficient fireplace insert.

Source: CMHC