Mark Ligon

Check valves are found in and around a pump system, a sump pit, or cracked open a main line. They’re everywhere. And there’s a reason they’re there: to prevent backflow. Backflow isn’t just unpleasant—it’s a serious hazard. It occurs when water or other liquids flow in the opposite direction, contaminating clean systems.

Here's what you need to know about venting for tankless water heaters and how you can approach it for the least cost and best results.