Gas Appliance Safety

It's extremely important that residents understand potentially deadly problems with gas appliances, such as gas furnaces and gas hot water heaters that are not installed and maintained according to the manufacturer’s listing and installation/operating instructions. This includes:

Proper Combustion, Ventilation and Dilution Air

One of the most important requirements for proper operation of any gas furnace and/or gas hot water heater is combustion air used for combustion, ventilation and dilution of flue gases, installed in compliance with Section G2407, I.R.C., along with the appliance manufacturer’s listing and installation/operating instructions. Combustion air ventilation can be broken down into two major categories:

A. Combustion Air Venting

Combustion air venting includes the proper removal of burnt combustion gases (thru the venting system) to the building’s exterior.

B. Combustion Air Inlet

Combustion air inlet allows proper quantities of air to reach the equipment burners.

Safe and efficient gas appliance combustion requires a proper air to gas ratio. Excessive combustion air may cause over-firing of the furnace, which can result in maintenance, reliability, and safety issues. Inadequate combustion air can result in the same sort of problems and in addition, can produce carbon monoxide, a colorless and odorless gas that is deadly even in very small quantities. Unfortunately, hundreds of people die from CO poisoning every year. This doesn't have to happen. Know the symptoms of CO poisoning: headache, dizziness, weakness, nausea, vomiting, sleepiness and confusion.

The City highly recommends homeowners consider the use of listed carbon monoxide (CO) alarms.

Inadequate combustion air is often the result of a failure of the flue system and/or the combustion air inlet system. Therefore, always have your gas appliances inspected and serviced for proper operation at least once a year (preferably before seasonal start-up), including checking to see that the required air grilles on the door of a gas appliance enclosure (furnace and/or hot water heater) remain clear and unobstructed, and that required combustion air openings in walls and/or ceiling are not covered or obstructed.

If your attic has had insulation recently added, check to see that any required combustion air vents that open directly to the attic space, have not been covered by the insulation application. In addition, because of the trend for homeowners to “tighten” their homes to achieve greater energy efficiency, the original air leakage in the home that aided in providing adequate combustion air, can inadvertently be diminished to the point where the gas appliance (furnace and/or hot water heater) now has inadequate combustion air. If in doubt, always check with your gas appliance service provider.

Gas Appliance Venting

Venting of any gas appliance (furnace and/or hot water heater) must be installed in compliance Sections G2425, G2426, and G2427 I.R.C. and with the appliance manufacturer’s listing and installation/operating instructions.

***Please note: Single wall gas venting may only be used within the gas appliance space and may not penetrate any adjacent wall and/or ceiling, and may not be installed in any wall cavity, floor/ceiling system, attic or any other concealed space. In addition, single wall gas vents must have a minimum clearance of 6 inches from any combustible material including gypsum wallboard.