Nearly every faucet replacement that goes badly goes badly for the same reason: the new faucet does not match the sink, or the shut-off valves under the sink have not been turned in fifteen years and refuse to close. Both are discoverable in a quarter of an hour, before you have spent any money.
Before you buy anything
Count the holes
Look at the deck of the sink. One hole means a single-hole faucet; three holes at 4 in. centres is "centerset"; three or four holes at 8 in. centres is "widespread". A single-hole faucet can be fitted to a three-hole sink using a deck plate (escutcheon). The reverse is not possible.
Test the shut-off valves
Turn both angle stops under the sink clockwise until they close, then open a tap upstairs. If water keeps flowing, or if the handle will not move, you need the house main shut off — and possibly the valves replaced, which is a separate job worth doing at the same time.
Measure clearance behind the sink
Tall gooseneck faucets look excellent and then hit the window sill when the handle lifts. Measure from the deck to the nearest obstruction and compare to the faucet's specified handle-clear height.
Check the sprayer and soap dispenser
If the old setup used a side sprayer in a fourth hole and the new faucet has a pull-down spray head, you will need a hole cover or a soap dispenser to fill the gap.
Look at the supply line ends
Most modern faucets come with integral flexible supply lines with ⅜ in. compression fittings. If yours does not, buy braided stainless steel lines of the right length — never reuse old ones.
Tool check
A basin wrench is the one specialised tool worth buying for this job. The mounting nuts sit four to six inches behind the bowl in a space no ordinary wrench reaches. They cost very little and turn a knuckle-shredding hour into ten minutes.
Tools and parts
- Basin wrench and 10 in. tongue-and-groove pliers
- Adjustable wrench, headlamp or work light, towels and a shallow tray
- Utility knife and a putty knife for old sealant
- Plumber's putty or 100% silicone sealant (check the faucet's instructions — many now specify silicone only)
- Two new braided supply lines if the faucet does not include them
- White PTFE tape for threaded connections only — never on compression fittings
If your toolbox is still being assembled, the starter tool list covers everything above except the basin wrench.
Shutting off and draining
Close both angle stops
Clockwise. If they are the older multi-turn type, they may weep slightly afterwards; that is normal and usually stops.
Open the faucet
Both handles, or the single lever to the middle position, to release pressure and drain the risers.
Clear the cabinet
Everything out. Put a towel and a shallow tray under the connections — there is always more water in the lines than you expect.
Disconnect the supply lines
Hold the valve body still with one wrench while turning the nut with another. Twisting an angle stop can crack a solder joint inside the wall.
Removing the old faucet
Disconnect the sprayer hose if there is one, then find the mounting nuts on the underside of the deck. On older faucets they are brass and often corroded; on newer ones they are plastic wing nuts you can turn by hand. Penetrating oil and ten minutes of patience beat force — a snapped mounting stud means removing the sink.
Lift the old faucet out and scrape the deck clean. Old plumber's putty comes away with a plastic putty knife; old silicone needs a blade and then a solvent wipe. The new seal will only be as good as the surface under it.
Do not skip this
While the deck is clear, this is the only convenient moment in a decade to replace tired angle stops with quarter-turn ball valves. It adds about thirty minutes and turns every future repair into a two-minute shut-off.
Installing the new one
Fit the gasket or seal first
Follow the manufacturer's instruction on putty versus silicone. Many modern faucets use a moulded rubber gasket and specifically warn against putty, which can stain composite and natural stone.
Feed the lines through
Thread supply lines and any spray hose down through the deck hole before seating the faucet body. Keep them from twisting.
Align, then tighten from below
Get the spout square to the sink edge by eye, hold it, and hand-tighten the mounting nut. Check alignment again, then snug with the basin wrench — firm, not heroic.
Connect the supplies
Hot to the left, cold to the right. Compression nuts go hand-tight plus roughly a quarter to a half turn with a wrench. Over-tightening is the single most common cause of a slow drip here.
Attach the spray head and counterweight
Pull-down hoses use a clip-on weight that must hang free below the sink. If it snags on the trap or a cabinet shelf, the head will not retract.
Testing and leak checks
- Remove the aerator from the spout. Debris dislodged during the work will otherwise clog it immediately.
- Open the angle stops slowly, a quarter turn at a time, watching the connections.
- Run cold, then hot, for two minutes each. Air will spit at first — that is normal.
- Refit the aerator, then dry every joint with a paper towel and press it against each connection. Damp paper finds leaks your eyes miss.
- Check again after twenty minutes, and once more the following morning. Slow drips take time to show.
Troubleshooting
| Symptom | Likely cause | Fix |
|---|---|---|
| Weak flow on both temperatures | Clogged aerator | Unscrew, rinse the screen, refit |
| Weak flow on one temperature only | Angle stop not fully open, or kinked supply line | Open fully; check line routing |
| Drip at a compression nut | Under- or over-tightened, or a damaged ferrule | Quarter turn tighter; if it persists, replace the line |
| Water under the deck plate | Seal not seated, or deck not clean | Remove, clean thoroughly, reseal |
| Spray head will not retract | Counterweight snagged | Reposition the weight so the hose hangs clear |
| Knocking when shutting off | Water hammer | Fit arrestors; unrelated to the faucet itself |
What it costs
A mid-range pull-down kitchen faucet runs roughly $110–$280. Add about $15–$25 for a basin wrench, $12–$20 for a pair of braided supply lines and $20–$30 if you replace both angle stops. A plumber typically charges $150–$350 in labour for the same swap.
When to call a licensed plumber
If the angle stops will not close, if the supply pipe is galvanised steel, if you find corrosion at a soldered joint, or if the sink is undermounted stone and the faucet mounts through the counter — stop. These are cheap problems to hand over and expensive ones to create.
Frequently asked questions
How long does it take to replace a kitchen faucet?
About 60 to 90 minutes for a straightforward swap with working shut-off valves and a basin wrench. Budget three hours the first time, and more if the angle stops need replacing.
Do I need plumber's putty or silicone?
Follow the faucet manufacturer's instructions. Many modern faucets ship with a moulded gasket and specifically prohibit putty, which can stain granite, marble and composite sinks. Where sealant is specified, 100% silicone is the usual choice.
Can I fit a single-hole faucet to a three-hole sink?
Yes — use the deck plate that comes with most single-hole faucets, which covers all three holes. Going the other way, fitting a three-hole faucet to a single-hole sink, is not possible without cutting the sink.
Should I reuse the old supply lines?
No. Braided stainless lines cost very little and are the component most likely to fail slowly and silently inside a closed cabinet. Replace them every time the faucet comes off.
