This picture shows a typical Spring Check Valve. If you have a pool Spring Check Valve installed in your pool circulation system and you notice water running backwards in your pool after you turn off your pool pump, you probably have a clogged Check Valve or one that has failed. With a clear Spring Check Valve, you can see if any debris is in the Check Valve mechanism that needs to be cleared out. See our guide on "How To Clear Debris From a Pool Spring Check Valve". Otherwise you can assume that the Check Valve has failed and needs to be changed. Most damaged Spring Check Valves cannot be repaired and must be replaced. This guide shows you have to replace a Spring Check Valve.