Like a stove, a water heater with a gas burner produces noxious fumes that contain carbon monoxide, a byproduct of the fuel used to ignite the burner to heat the water in the tank, whether that fuel is natural gas, oil, or propane. Just like your furnace, you need to have proper ventilation to vent the water heater's toxic fumes outside to keep you and your family safe.

On a standard gas water heater, the fumes are usually exhausted through the return air insert and flue. A return air insert prevents air from entering the top of the water heater and improves heat distribution in the tank. A flue is a vent through which smoke passes, allowing it to escape safely outside the home.

Water heaters that use atmospheric venting or direct venting will allow the smoke to escape naturally, either through a vertical vent that rises directly up the chimney of the home or through an upward-sloping vent that can pass through the chimney or wall to the exterior of the home. In both cases, the water heater needs to be located near an exterior wall or chimney for the ventilation system to work properly.

On some gas water heater models, an electric exhaust blower will be used to draw exhaust air into the flue. Power-vented water heaters are considered more energy efficient than standard direct-vented systems and are more effective at preventing return air from entering the water heater. Because power vents use a fan motor to draw exhaust air into the flue, the vent can be longer and more horizontal, which will give you more options for where to install your water heater.

While you should always check your local building codes to confirm the proper way to install your water heater vent, here are some general guidelines to follow:

- If your water heater relies on atmospheric or direct draft, you will need to use UL Listed Type B metal flue pipe that is three or four inches in diameter.

- Water heaters with a power vent system can be vented using PVC plastic pipe at least two inches in diameter, as the blower helps cool the air passing through, although some experts believe metal pipe is a safer choice.

- There shall be a minimum of 12 inches of vertical ventilation between the hood outlet and the first elbow or connector.

- When direct ventilation is used, the minimum upward slope of any semi-horizontal duct shall be one-quarter inch per foot. The half-horizontal distance shall not be greater than 75% of the total vertical height of the vent.

- Vent pipes need to be fully sealed where they pass through a wall or into a chimney to prevent air leaks.

- When venting through a chimney, a UL Listed chimney or cowl must be used at the point of termination.

A direct vent system will draw in combustion air from outside (through the exhaust vent), while a powered vent system draws in the indoor air around the water heater. Therefore, water heaters with power vents should not be installed in small, enclosed spaces.

If space constraints require the water heater to be installed in a utility closet, make sure the closet door has shutters or leaves space at the top and bottom of the door for increased air circulation.

Power vent systems may require sloping exhaust vents to properly drain condensation that has accumulated in the ductwork.

Because gas water heaters use open flames, keep flammable materials, such as paint cans, away from the unit.

Since there is always the possibility of a gas water heater or furnace exhaust leaking, one or more carbon monoxide detectors should be installed near bedrooms in your home. Detector batteries should be checked periodically.

The above briefly introduces some precautions for discharging gas water heaters. If you want to buy a gas water heater, please contact us.

Greidea is a professional gas water heater manufacturer. We have more than 20 years of experience in manufacturing, R&D and customization. Our gas water heater factory is located in Shunde, Foshan City. In our R&D department, 12 engineers are hired to guarantee our R&D advantages and innovation advantages. Test rooms and assembly lines have been upgraded. Spend 3% of revenue annually on research and development. With an excellent manufacturing team and quality control team, we have achieved an annual output of 500,000 best quality gas water heaters.