I have an older house with lots of pinhole leaks in the copper pipes. From what I have been told, you have to replace the pipes, copper or PEX or maybe something else. I am trying to avoid the ~$10k to do this, not that it is not worth that or that people shouldn't be paid, but it is a lot for me.
Can I replace the copper a little bit at time, maybe one bathroom, a kitchen and a hammer arrestor to stuff, etc.? Do I have to go in full throttle with manifold and do it all at once? I'm concerned on some of it because copper comes out of the water tank, and I don't know if I can mix things up down the line, or if I have to start at the tank with PEX, then I have the Pressure/expansion tank.