Hey, Tony.. I put one (Shurflo Smart Sensor 4.0) in a few months ago and it is very quiet.. It draws a very little current while it is not working, 15 milliamperes claimed, and a good bit less when running at the same flow than the old one did. It takes the sensor a second or two to realize it needs to run so when you open the faucet, the flow is slow for about 2-3 seconds then it comes up.. Different and annoying at first, but I am OK with it now. My old Shurflo 225-3000 lasted 20 years.