Step 3 · Loosen the PRV Locknut
Locate the water pressure reducing valve. It is a brass, bell-shaped device installed on the main water line, typically just after the main shutoff valve and water meter. On top of the 'bell' housing, you will find the adjustment mechanism, which consists of a long threaded screw (the adjustment screw) and a nut at its base (the locknut). Using your adjustable wrench, turn the locknut counter-clockwise to loosen it. You only need to loosen it a few turns to allow the adjustment screw to move freely.