Step 7 · Test for Leaks
Before closing up the wall, it is imperative to test your work. Ensure the new valve is in the closed (off) position. Go back to the main water shut-off valve and turn it on slowly. Listen for the sound of pipes filling. Return to the shower and use a flashlight to meticulously inspect every single new solder joint and connection for any signs of moisture or dripping. Let the system sit under pressure for at least 10-15 minutes. If any leak is detected, shut off the main water supply again, drain the pipes, and correct the faulty joint.