Hello, quick question for the experts out there. I live in the midwest and have a sump pump in the basement. PVC from sump pump runs up the basement wall and across a 10 foot ceiling section and connects directly to the city sewer system underground (I think). Our sump had been making a BANGING noise at the end of each cycle. Reading up about that, I determined it must be a bad check valve. Replaced that myself. Still a lot of vibration. Had a plumber come out...he recommended a new sump pump as our home is 12-years old. Plumber installed that, and told me to secure the ceiling PVC better to remove vibration. Winter came and I forgot about it. ;( Now that we've had some thaws, vibration came back worse than ever. I got some hangers and secured the PVC as solid as possible. Now, the vibration is localized to the check valve, and it lasts like 30-45 seconds after the pump cycles. No banging, just loud vibration. I had saved the original check valve, which the plumber had said was still good. I put that back on, and all was quiet, until I noticed it was leaking around the upper rubber flanges. I tightened it down and now it's the same...massive vibration localized to the check valve after a cycle, lasting around 30-45 seconds. Any ideas what's happening?