I have had a Rinnai tankless heater for 5 years with ZERO problems and absolutely love it's performance. Just had it flushed by a professional for the first time this spring. He couldn't believe the small amount of material that came out of the heat exchanger with him knowing that my water is in the 40 grains (considered extremely hard) of hardness range. I have a 45,000 grain softner (salt) installed at the same time that has also worked without problems. I have not had any corrosion problems with appliances, fawcets, or fixture problems , etc. Can anyone that has an Easy Water system tell me their experiences with that product. If you listen to Easy Water's advertising closley, they claim to slove "most" hard water problems but they don't claim to soften water.