Tankless water heaters offer the option of venting through an exterior side wall instead of through a chimney flue on the roof. Water heaters that are direct venting have two vents — one that pulls in air from the outside and one that carries away exhaust. Power venting water heaters draw air from inside the room and have only a single vent for exhaust. While non-condensing tankless water heaters require thick metal venting to handle the temperature of heat that's released, condensing tankless water heaters can use plastic venting such as PVC. They have already used the hot vapors to heat more water, leaving only cooler fumes for ventilation.

A. O. Smith tankless water heaters boast industry-leading 15 year limited warranties. While the lifespan of a gas tankless water heater can vary, factors like water conditions, usage rates and maintenance all contribute to your water heater’s health. New condensing units come equipped with X3® Scale Prevention Technology that extends life up to three times longer.

Tankless water heaters have different flow rates measured in gallons per minute (GPM), which indicate the amount of water they can deliver at a time. Because these water heaters don't maintain a supply of hot water in a tank, you need to choose an appropriately sized tankless model based on household needs. The ideal output rate for your home depends on the number of people in the residence, the appliances you use, and the original temperature of the water being heated. Some people install more than one tankless water heater based on their requirements. Check out our water heater selector to help choose the best water heater for your needs.

• What do I need?
• Before installation, you will need to determine the incoming ground water temperature, the ideal location in your home, and the correct water heater size required for your needs.
• Where to install?
• A tankless water heater can be installed anywhere in your home with the correct piping—closets, garage, bathrooms, etc. In warmer climates where there is no risk of freezing, a tankless water heater may be installed on the exterior of the home to save on interior space.