adel_ava

I just installed an Intelliflo VF and a few days later a new FNS 48. When the pump is shut down and I open the pressure relief it pulls a vacuum and siphons the filter water and DE back through the pump, pump suction line and into the pool. Checked with leak detect on all the joints and did a low tech hydrostatic test on the suction line. No suspected leaks. 70-643 Based on what repair guy answered in the post below and my suspicions that's its a simple gravity flow issue. I'm installing a check valve on the pump discharge to filter inlet line tomorrow. Have to see after if it works or if the filter/DE water will then siphon through the return line. 642-145 Not 100% happy with the clamp fitting on the FNS. Seems I have to tighten down 8 or more turns past where the spring coils are touching to stop minute leaks around the clamp. Tapped with a rubber mallet while tightening, O-ring lightly silicone lubed. Perhaps if Deeker sees this he may have a suggestion. 642-873 I'll let you know if the check valve solves the problem, although I'm still am suspicious I have a leak.