Tools You’ll Need Before you start, gather an adjustable wrench, a flathead and Phillips screwdriver, plumber’s grease, and a replacement washer or O-ring kit (available at any hardware store — bring your old part if unsure which size to buy). How to Fix a Leaky Faucet Step-by-Step When to Call a Plumber Instead If the leak continues after replacing the washer, or you notice corrosion, cracked pipes, or low water pressure throughout the house, it’s worth calling a licensed plumber. According to the EPA’s WaterSense program, household leaks waste over a trillion gallons of water nationwide each year, so it’s worth fixing promptly either way. Final Thoughts Knowing how to…