How to Install a Faucet: 5 Steps (and Why Homeowners Call a Pro)

Installing a new faucet looks simple in a hardware store demo, but a few details trip up most first-time DIYers. Here's the process, and where it tends to go sideways.

1. Confirm Compatibility First

Before buying, check your sink's hole configuration (single-hole vs. widespread) and your existing supply line connections. Buying the wrong style is the single most common mistake.

2. Shut Off and Disconnect the Old Faucet

Shut the supply valves under the sink, disconnect the old supply lines, and remove the mounting nuts — often the hardest part, since these are frequently corroded or hard to reach.

3. Clean the Sink Surface

Old plumber's putty or caulk residue needs to come off cleanly for the new faucet to seal properly against the sink or counter.

4. Install the New Faucet and Connect Supply Lines

This is where mismatched thread sizes or worn valves often surface — sometimes requiring new supply lines or even valve replacement that wasn't part of the original plan.

5. Test for Leaks

Turn the water back on slowly and check every connection, including under the sink, before considering the job done. A slow leak that goes unnoticed for weeks can cause real cabinet damage.

Why Homeowners Often Call a Pro

The parts that go wrong — a corroded shutoff valve that won't turn, a supply line that doesn't match the new faucet's fitting, an unexpected leak after reconnecting — are exactly what a plumber handles routinely and a first-time DIYer doesn't have parts on hand for. A professional install is typically done in under an hour with everything needed already on the truck. See our faucet installation page for a free quote — bring your own faucet or ask us for a recommendation.

Reviewed by the Rush Plumber team — licensed, insured plumbers serving Torrance, CA and the South Bay, 3610 Torrance Blvd, Torrance, CA 90503. Call (209) 860-5004, 24/7.