I had to replace my water heater. I had a water softner hooked up but valve was in the bypass position due to quit working years ago. So I decided to run new lines and by pass the softner. But when I open valve to cold water to check for leaks all faucets started spitting out redish water and I ran it for about 10 minutes and still redish water. What can I do.

Go back and check your piping layout. It sounds like you connected the softener back into the system. You might also check the aerator screens on the faucets that were spitting. Good luck, Tom