Do I need to upgrade my gas line? Does a tankless water heater use more gas?
The minimum gas line size is inside diameter. To heat the water quicker and more efficiently, tankless water heaters operate with higher BTUs and require a minimum gas line. This does not mean that a tankless water heater uses more gas. Because tankless units heat water on demand they require higher BTUs (or they operate on high heat). This requires a greater jolt of gas, and therefore, a minimum gas line. On the other hand, because tanks are constantly heating water (or they operate on low heat), they require a constant supply of gas.
ANSWER The minimum gas line size is inside diameter. To heat the water quicker and more efficiently, tankless water heaters operate with higher BTUs and require a minimum gas line. This does not mean that a tankless water heater uses more gas. Because tankless units heat water on demand they require higher BTUs (or they operate on high heat). This requires a greater jolt of gas, and therefore, a minimum gas line. On the other hand, because tanks are constantly heating water (or they operate on low heat), they require a constant supply of gas.
