Step 9 · Inspect and Test

This is the step people usually slow down on. Go finger-tight first, then a quarter turn. No rush — replay the clip whenever it helps.

Perform a final visual inspection of your work. A good solder joint will have a smooth, shiny, and continuous bead of solder visible all the way around the seam. There should be no pinholes, gaps, or large drips. After inspecting all your new joints and ensuring they are cool, it's time to test for leaks. Close all the faucets you opened to drain the system, except for the one at the highest point in the house. Go to the main water shutoff and open it very slowly and only partially. You should hear the pipes begin to fill with water. Let the air escape from the highest faucet until a steady stream of water comes out, then close it. Now, fully open the main shutoff valve. Carefully check every new joint for any sign of water, from a slow drip to a fine spray.