Gas Water Heater Vent Types

Explore different vent types, how they work, and what you’ll need to install them.

While not all State water heaters need venting in your home, gas water heaters do require venting with the correct venting materials and setup. When you have identified the correct venting for your application, you’ll help make sure your water heater runs safely and efficiently. Be sure to consult a professional plumbing contractor to ensure you have the correct venting option for your water heater.

Standard Atmospheric Vent

The most common type of residential gas water heater is a standard atmospheric vent type. Standard atmospheric venting uses a vertical or upward sloping metal duct vent to vent exhaust out of the home. Other atmospheric vent appliances, such as a furnace, may share the same vent system, or they can use dedicated vent systems on their own. The venting is oriented vertically because hot air rises, helping the hot exhaust to rise safely and exit the home.

Power Vent

State power vent gas water heaters come with an electric blower fan installed atop the unit. This requires an electrical outlet near the water heater. The blower forces the exhaust heat through the exhaust venting, which can be installed either vertically or horizontally with a longer line. This provides more flexibility in where the water heater is located in the home.

Power vents use more of the exhaust heat to heat water, so they represent a more efficient option designed for energy savings. With lower exhaust temperatures, power vents also make it possible to use PVC piping. This is a more cost-effective solution than standard atmospheric vent metal piping, and it’s also simpler to assemble. We recommend that you contact a professional plumbing contractor to determine your ideal solution and complete the installation process.

Power Direct Vent

When you install a water heater in a space with insufficient air for combustion, a power direct vent may be required. Similar to direct venting, power direct venting uses a blower to pull in air from outside the home directly to the water heater to use for combustion. The blower also expels the exhaust gases outside the home through a second vent pipe. Similar to power vents, power direct vent water heaters can use PVC piping, which can lower installation investment. They do require an electrical outlet to be in close proximity to the water heater.

Reach out to a professional plumbing contractor to find out if your home and water heater require power direct venting.

Direct Vent

When there isn’t sufficient ventilation for the area around your water heater, direct vent gas water heaters are a great choice. These types of water heaters bring in air for combustion from outside the home instead of using air from within your home. When exhaust gases and extra heat are produced from your water heater, they are vented outside the home again.

Special coaxial venting is required for direct vent water heaters. This type of venting has separate chambers for pulling air in and expelling exhaust, all assembled in one vent piece. Running from the water heater through the side of your home, coaxial venting pulls and pushes air from outside the home to prevent backdrafting within your home. This feature lowers safety risks for the installation and use of a gas or liquid propane tank water heater.

We recommend that you contact a professional plumbing contractor to find your ideal solution and complete the installation process.

Concentric Vent Termination
Concentric Vent Full Run

Concentric Vent

A concentric venting system may be the best option for use with many types of water heaters, including direct and power direct vent as well as tankless. While the material of a concentric vent may differ depending on the type of water heater you have, this aesthetic installation option refers to any coaxial “pipe in pipe” design. This means simply that the intake air and exhaust gas move through separate chambers of the same assembly.

For water heating units, such as direct vent or concentric vent tankless, concentric venting may be used for the entire vent run, from the water heater to outside the home.

Concentric vent terminations offer the aesthetic benefits of a single wall or roof penetration, and they can be used with power direct vent or tankless water heaters. For these installations, separate pipes for intake and exhaust run between the water heater and inner wall, and concentric piping is used only for the wall penetration and termination.

For installation of concentric venting, we recommend that you consult a professional plumbing contractor

Additional Reading

State water heaters come in a large range of sizes. Discover the factors to consider when making your decisions.

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How can the quality of your water affect your water heater? Get tips and more information on water hardness, why it matters, and how to solve it.

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Discover the innovative design features A. O. Smith engineers use to keep your water heater both functional and safe.

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