[villagetinker]

For the drains, I just did my own, liquid plumber, followed the directions and drains flowing like new. As for the pop on/off valves, I would not replace unless you are having problems. If the valves are turning OFF, check your expansion tank it has probably failed. The simple test, tap on the side of the tank, below the weld the sound should be dull, above the weld it should be sharp like a bell.