“I bought this item for a local hardware store and installed it. After a week or so notice a water hammer or loud thumping noise kind of like a compressor running when ever the washer was started. Then noticed it with any single lever faucet or mixing valve. The customer support at cash acme was friendly but not very helpful. I did research and found that the air that entered the plumbing system during install could be the culprit. I closed the main water supply valve. I drained the system form the lowest hose bib/or faucet on the house, opened all other faucets/showers/tubs both hot and cold and flushed all the toilets. Then opened the main supply valve ever so slightly to begin filling the system. Then starting from the faucet/hose bib or lowest water outlet farthest from the main water supply. Wait for water to start flowing and then when it is steady close it off. Then start working your way back towards the main shutting off valves/faucets/hose bibs excreta one at a time after water has stated to flow. The idea is to bleed out all the air. After all are closed and toilets have filled and you don't hear any more water flow, open the main all the way. Always good to go back around a check for leaks. It has solved my problem. Good luck”