A kitchen faucet replacement is one of the highest-value plumbing upgrades a homeowner can do. The faucet is the most-used piece of hardware in the kitchen — touched 30+ times daily. A quality replacement (Moen, Delta, Kohler) lasts 15-25 years; cheap big-box faucets fail in 3-5. The install is genuinely 1-2 hours including drying and testing, with no permits required for like-for-like replacement.
This guide covers a single-handle pull-down kitchen faucet (the most common modern style). Two-handle, pull-out, and bridge-style faucets follow similar steps with different fitting details.
Before you start
Three things to settle:
1. Number of mounting holes. Existing kitchen sinks have 1, 3, or 4 mounting holes. Single-handle modern faucets typically need only 1 hole. If your sink has 3 holes (typical) and you want a single-handle faucet, you'll have 2 unused holes — fill with a 'deck plate' (often included with the faucet) that covers the unused holes, OR with separate filler caps. Plan before buying.
2. Supply line connections. Modern faucets typically come with pre-attached braided stainless steel supply hoses with 3/8-inch compression fittings. If your existing shut-off valves are 3/8-inch (standard), the new faucet plugs in directly. If they're 1/2-inch (older homes), adapters are needed.
3. Spray hose and weight. Pull-down faucets have a hose that retracts back into the spout when released. The hose passes through a hole in the faucet body and through a weight that pulls the hose back. The hose threading and weight installation is the most-fiddly part of the install.
What you'll need
Tools
- Adjustable wrench OR plumber's basin wrench (highly recommended for tight spaces under sinks)
- Slip-joint pliers
- Bucket and old towels (for residual water)
- Flashlight or headlamp (under-sink work is dark)
- Plumber's tape (Teflon)
- Phillips and flat-head screwdrivers
Materials
- New kitchen faucet (matching mounting holes and meeting your style)
- Replacement supply lines (often included; verify length matches)
- Plumber's putty or silicone caulk (for sealing the faucet base to the sink)
- Deck plate or filler caps (for unused mounting holes)
A basin wrench is the install difference
Basin wrenches are specialty tools designed for the cramped under-sink space. They have a long shaft and a swivel head that grips nuts you can't reach with a standard wrench.
Inexpensive and stocked at any hardware store. Without one, the install is significantly harder. Worth buying for any kitchen or bathroom faucet job.
Step-by-step instructions
Shut off water and disconnect supply lines
Find the shut-off valves under the sink — typically two valves, one for hot, one for cold. Turn each clockwise to close.
Open the faucet to relieve pressure. Disconnect the supply lines from the existing faucet using slip-joint pliers — typically the supply nut at the bottom of the faucet's tail pipe.
Disconnect the existing faucet from the sink
Below the sink, find the mounting nuts holding the faucet down. These thread onto the faucet's tail pieces from below.
Use a basin wrench to loosen the mounting nuts (counterclockwise). Remove the nuts and any washers.
Lift the old faucet up out of the sink. The supply hoses and any sprayer hose come up with it.
Clean the sink mounting area
Remove old plumber's putty, mineral deposits, and grime from the sink's faucet mounting area. The new faucet must seat against a clean surface.
Wipe down with a non-abrasive cleaner.
Prep the new faucet (deck plate, hoses, etc.)
If the new faucet uses a deck plate (covers unused holes), attach it to the faucet base per instructions. Apply the included gasket or silicone bead between deck plate and sink.
Thread supply hoses, spray hose, and any other components through the faucet body before lowering into the sink.
Position the faucet in the sink
Lower the faucet into position, aligning with the mounting holes. The hoses pass through the holes and hang below.
Hold the faucet upright while a helper (or you reaching from below) installs the mounting hardware.
Install mounting hardware from below
Below the sink, slide on washers and thread mounting nuts onto the faucet's tail pieces.
Use a basin wrench to tighten — typically hand-tight plus a quarter to half turn. Don't over-tighten; the nuts crack.
Confirm the faucet sits flush against the sink with no rocking.
Connect supply lines
Connect the hot supply hose to the hot shut-off valve and cold to cold. The faucet will be marked which is which.
Apply Teflon tape on the threads if compression fittings — usually a few turns. Hand-tighten the supply line nuts, then snug a quarter to half turn with a wrench. Don't over-tighten compression fittings; they leak when stripped.
Install spray hose and weight (pull-down faucets)
Thread the spray hose through the faucet body and through the included weight.
Per the manufacturer's instructions, position the weight so the hose retracts smoothly into the spout when the spray head is released.
Test by pulling the spray head out and letting it return — should retract smoothly without snagging.
Apply plumber's putty or silicone around the base
If your sink/faucet design uses plumber's putty or silicone for the seal between faucet base and sink, apply per the manufacturer.
Putty: roll into a 1/4-inch rope, place around the base before lowering. Excess squeezes out and is wiped clean.
Silicone: thin bead around the base. Tighten the mounting nuts; clean excess with a damp cloth.
Restore water and test for leaks
Open both shut-off valves. Watch for leaks at the supply line connections — drip or seepage indicates loose nut or insufficient Teflon tape.
Open the faucet (single handle to centre, or both handles for two-handle) — water should flow.
Check thermal: hot side should be hot; cold should be cold. Reversed indicates supply lines connected backwards.
Test full flow and spray modes
Run hot, cold, and warm. Verify smooth flow, no spitting, normal pressure.
Test spray modes if applicable (stream, spray, pause). Confirm spray head retracts cleanly into spout.
Common mistakes that cost you
- No basin wrench. Standard wrenches don't reach. Basin wrench is essential under-sink tool.
- Over-tightening compression fittings. Strips and leaks. Hand-tight plus quarter to half turn.
- Hot/cold supply reversed. Hot comes from cold tap, etc. Reverse the supply lines.
- Skipping the seal at the base. Water gets under the faucet and rots the sink mounting area. Always seal base to sink.
- Wrong number of mounting holes. Modern single-handle faucet on 3-hole sink without deck plate looks unfinished. Plan deck plate before buying.
Frequently asked questions
Single handle or two handles?
Single handle: most modern, easier to operate one-handed (carrying dishes, holding kids), single point of leak risk.
Two handles: traditional, more precise temperature control, double the points of leak risk over years.
Most modern kitchens go single-handle for convenience.
Should I get a pull-down or pull-out spray?
Pull-down: longer reach into the sink, better for filling pots in the sink, but the hose is exposed when extended.
Pull-out: shorter pull but hides hose better, classic look.
Both perform similarly; pick based on aesthetic preference.
Do I need a permit?
Like-for-like faucet replacement: no permit. Adding new shut-off valves, replacing supply piping, or running new water lines: typically yes — plumbing permit required.
When to call us instead
If your shut-off valves are old/leaking, supply lines are corroded, or the sink mounting itself is damaged, this becomes a bigger plumbing job. We do kitchen plumbing as part of full kitchen renovations.
Book a free 60-minute site visit →Related Ottawa services
If you're refreshing the kitchen comprehensively, our kitchen renovation team handles plumbing, fixtures, and finishing as fixed-price scopes. Book a free 60-minute consultation.