We have hot and cold copper pipes that feed our washer and then further down a washing sink in our basement. There are two valves on each pipe, and above the valve on the cold water pipe, the pipe is turning very blue for about 30 inches (The place above the pipe is closer to the source of the water than is the pipe below the valve.) Above the hot water pipe, it is somewhat discolored (again "above" is closer to the source of the water), but not nearly as bad. Also, past those two valves (further away from the water source), there are two valves that directly control the water entering the washer. The valves are maybe eight inches from the higher valves, and the pipes from the initial valves to the washer valves are not discolored.
We bought our house 3.5 years ago, and the owner had a note on the basement wall stating that after the washer was used, the washer valves should be turned off. The valves are a little old, so we have always kept them open all the time (fearing that they would leak if we closed them). Could someone tell me what is going on with the blue pipe, and how we can prevent further damage?
Thanks,
JD