That “thumping” or “clunking” sound is usually “water hammer” caused by a failing or cheap check valve. A check valve ensures that once water is pumped out, it doesn’t flow back down into the basin when the pump turns off. Without a high-quality “Silent Check Valve,” the pump has to work twice as hard to remove the same water, leading to motor burnout. At Basement Expert, we install premium, quiet-close check valves that protect your pump’s lifespan and keep your basement quiet.