A previous post discussed leaks that occur while your swimming pool pump is running. Such leaks almost always tend to occur on the return side of the system–in other words, somewhere in the network of pipes leading from pump back to pool. Yet leaks can also occur on the suction side of your system. If you would like to learn more about what causes such leaks, read on. This article will explain the basis of suction side pump leaks.
Suction Side
As its name would imply, the suction side of your system has the job of drawing water up out of your pool toward the pump. In the process, the water passes through a series of PVC pipes–pipes which have a tendency to develop leaks over time. Yet these leaks confuse many people, since they do not seem to occur when the pump is running. Rather they only show up once the pump has shut down.
Vacuum Forces
To understand why suction side leaks only happen when the pump is off, it helps to first consider what is happening when the pump is on. The action of the pump generates a vacuum inside of the suction side pipes. This vacuum is what physically pulls the water out of your pool. Its force is so great that, while the pump is running, the water courses through the pipes too quickly to escape through any leak points that may be present.
When the pump shuts off, there is still a significant amount of water in the suction side of the system. Yet the vacuum force that pulling it forward has suddenly ceased to exist. Thus the water is now free to find its way out of the pipes through cracks and holes. The best way to diagnose a suction side leak–aside from finding the place where water is escaping–is to watch the water inside of the pump while it is running. If you notice that the water appears frothy and/or bubbly, this indicates that air is being sucked into the system through a leak somewhere on the supply side.
For more assistance in locating and repairing a leak in your pool system, please contact the pros at Alan Jackson Pools.