We built our house in November 2019 and went with a tankless hot water heater (runs off propane). It has been great. Recently our local telephone/internet service guy was at the house and we were talking. He said that he was advised to "flush" the system every few years especially if you are on a well. He said there is a special piece of equipment you use. Is anybody familiar with this? This is the first experience I have ever had with tankless. Thanks