If it is a vari-flow valve, this usually implies a bad gasket. With the valve set to "filter" and the pump OFF you can remove the screws on the top of the valve to check the gasket. It looks like a pie-chart, and usually called a "spider gasket". Check the gasket for tears or warps in the rubber, if you find any replace the gasket. A bad gasket will cause water to flow into different pipes. Turning the valve while the pump is running will cause these gaskets to fail
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If it is a vari-flow valve, this usually implies a bad gasket. With the valve set to "filter" and the pump OFF you can remove the screws on the top of the valve to check the gasket. It looks like a pie-chart, and usually called a "spider gasket". Check the gasket for tears or warps in the rubber, if you find any replace the gasket. A bad gasket will cause water to flow into different pipes. Turning the valve while the pump is running will cause these gaskets to fail