If your swimming pool filtration system turns on but fails to circulate water as it's supposed to, address the problem quickly, because the filter can suffer permanent damage if it continues to run without circulating water. Fortunately, there are only a handful of problems that can cause this, including a clogged filter, a low water level or a pool line blockage. It's relatively easy to determine what the problem is and to fix it.
Low Water Level
The water level in your pool is extremely important in terms of proper filter operation. The filter is designed to run in a vacuum situation with water filling the entire system; if air enters the system, the motor can become damaged. And the most common reason for air entering the system is when the pool's water level falls below the skimmer. When this happens, water must be added immediately, because without an adequate water level, circulation will be nonexistent. If this happens, turn off your filter pump, and raise the water level so it is at the halfway mark of the skimmer before turning the pump back on.
If you live in a windy climate or have the pool sitting beneath a tree, you already know that leaves in the pool are a persistent problem. If you neglect the pool and leaves continue to fall on the water's surface, they eventually make their way into the skimmer basket, which will clog the lines and cause a loss of water circulation. Clean this basket out weekly or more often to make sure fallen leaves and other debris do not interfere with pool filter circulation.
Water will fail to circulate when the filter system has become dirty and clogged. Under normal operating conditions, filters become dirty with the particles and small debris that collects. Backwashing your filter is necessary when the pressure gauge on the filter rises 8 to 10 pounds per square inch (psi) past its normal operating pressure. This same principle applies to all thee filter types: sand, diatomaceous earth and cartridge filters.
Pump Basket Clogged After Vacuuming
When you vacuum your pool to pick up dirt and debris that has settled to the pool bottom, you typically remove the skimmer basket to fit the vacuum attachment into the skimmer. With this basket missing, debris may flow into a secondary basket on the pump itself. If this pump basket becomes clogged after vacuuming, it must be cleaned out, because larger pieces of debris may have migrated here.