Replacing a Kitchen Faucet Without Calling a Plumber

A faucet replacement is one of the more approachable plumbing jobs because it rarely involves cutting pipe, but the working space under a sink is what makes it harder than it should be. Planning for that constraint in advance is what separates a one-hour job from an afternoon of frustration.

Tools that actually help

• Basin wrench — the single tool that makes reaching the mounting nuts behind the sink bowl possible.
• Adjustable wrench and channel-lock pliers for supply line connections.
• Bucket and old towels for the water that sits in the lines even after shutoff.
• Plumber's putty or the manufacturer's supplied gasket, per the new faucet's installation instructions.
• Flashlight or headlamp — cabinet lighting under a sink is almost always inadequate.

Step-by-step

1. Shut off both hot and cold supply valves under the sink, then open the faucet to release remaining pressure.
2. Disconnect the supply lines from the old faucet's shutoff valves and from the faucet body.
3. Use a basin wrench to remove the mounting nuts holding the old faucet to the sink deck.
4. Lift out the old faucet and scrape away old putty or gasket material from the sink deck.
5. Set the new faucet's gasket or apply plumber's putty per instructions, then feed the faucet's lines down through the mounting holes.
6. Hand-tighten the mounting nuts from below, then snug with the basin wrench.
7. Connect new supply lines (buy new flexible lines rather than reusing old ones) to both the faucet and the shutoff valves.
8. Turn the water back on slowly, check every connection for drips, then run the faucet for a minute to clear debris from the lines.

Matching the mounting holes to the new faucet

Sinks are typically drilled for one, three, or four holes. A single-hole faucet installed on a three-hole sink needs a deck plate to cover the extra holes, usually included with widespread-style faucets or sold separately. Measure the existing hole spread before buying a new faucet to avoid a mismatch discovered mid-installation.

Dealing with corroded old shutoff valves

If the shutoff valves themselves are old, corroded, or do not fully stop water flow, this is the point to replace them rather than fighting a partial leak later. Quarter-turn ball valves are more reliable long-term than older multi-turn compression valves and are inexpensive to swap while everything is already disconnected.

After installation checks

Worked example: budgeting the whole swap

A mid-range single-hole pull-down faucet plus two new braided supply lines is a modest materials cost, and most kits include the mounting hardware. Active work runs 1-2 hours for someone doing this the first time, most of it spent working by feel under the sink rather than dealing with the faucet itself. Add 20-30 minutes if the old shutoff valves need replacing at the same time.

• Common mistake: forgetting to drain water sitting in the supply lines before disconnecting them, soaking the cabinet below.
• Common mistake: over-tightening plastic mounting nuts, which can crack under a wrench meant for metal fittings.
• Common mistake: reusing old, already-compressed supply lines instead of buying new ones.
• Common mistake: not checking hole spread before ordering a new faucet, then discovering it doesn't match the sink's existing holes.

Run both hot and cold at full flow for several minutes, check under the sink with a dry paper towel run along every connection to catch a slow drip that is not visible by eye, and recheck again after a day of normal use since some fittings need a second snug-down once components settle.