What You Need to Know Before Starting
Replacing a Delta kitchen faucet is a job you can do yourself in one to three hours with basic tools — no plumber required. The process involves shutting off the water supply under the sink, disconnecting the old faucet, and installing the new one in its place. Delta faucets come in several styles (single-handle, double-handle, pull-down), but the removal and installation steps are nearly identical across all models.
Before you begin, check whether your new Delta faucet will fit your existing sink holes. Most kitchen sinks have either one hole (for a single-spout faucet) or three holes (for a faucet with a separate sprayer or handles on each side). If your sink has two holes and your new faucet needs three, you will need a deck plate to cover the gap. Delta includes this information in the box, and the instruction sheet that comes with your faucet is your most reliable reference — keep it nearby while you work.
Key Takeaways
- Turn off the water supply valves under the sink before disconnecting anything, and test that the water is truly off by turning on the faucet.
- Use an adjustable wrench or basin wrench to loosen the mounting nuts under the sink; a basin wrench reaches tight spaces better than a standard wrench.
- Disconnect the hot and cold water supply lines by turning them counterclockwise, and place a bucket underneath to catch any remaining water.
- Install the new faucet by reversing the removal steps: insert it through the hole, hand-tighten the mounting nuts, connect the supply lines, and turn the water back on.
- Test for leaks at all connection points before you consider the job complete, and keep the Delta instruction sheet for reference if problems arise later.
Gather Your Tools and Materials
You will need an adjustable wrench (or ideally a basin wrench, which has a long handle designed to fit under sinks), a bucket to catch water, and possibly a screwdriver. A basin wrench costs $10 to $20 and makes the job much faster if you plan to do this work more than once; an adjustable wrench works but requires more contortion under the sink.
Have a towel or old cloth nearby to wipe up spills. If your new faucet came with mounting hardware, lay it out in order before you start — Delta packages these parts in a specific sequence for a reason. Read through the instruction sheet that came with your new faucet; it will show you exactly which parts go where and in what order.
Turn Off the Water and Disconnect the Old Faucet
Look under your sink for two shut-off valves, one for hot water and one for cold. They are usually oval knobs or small levers on the pipes coming up from the wall or floor. Turn both valves clockwise until they stop — do not force them. Then turn on the kitchen faucet at the sink above to release any pressure in the lines. Water may still drip; this is normal.
Place a bucket under the water supply lines. Use your wrench to turn the connection nuts counterclockwise — these are the fittings where the supply lines attach to the faucet. You may need to hold the fitting with one wrench while turning the nut with another to prevent the line from twisting. Once both lines are loose, set them aside in the bucket.
Now loosen the mounting nuts that hold the faucet to the sink. These are under the sink, attached to the faucet body. Use your basin wrench or adjustable wrench to turn them counterclockwise. Once they are loose enough, you can usually unscrew them by hand. Lift the old faucet straight up and out of the sink hole.
Clean the Sink and Prepare for the New Faucet
With the old faucet removed, you will see the sink holes and any old caulk or debris around them. Wipe the area clean with a damp cloth. If there is old caulk, scrape it away with a plastic scraper or old credit card — do not use a metal blade, which can scratch the sink. The mounting surface should be dry and clean so the new faucet sits flush.
If your new faucet comes with a rubber gasket or deck plate, place it on the sink now, centered over the holes. This prevents water from running down between the faucet and the sink. Some Delta faucets have the gasket built in; check your instruction sheet.
Install the New Faucet and Reconnect the Water Lines
Insert the new faucet through the sink hole from above. The spout should point forward, and any handles should be positioned where you want them. From underneath, slide the mounting hardware onto the faucet body in the order shown in your instruction sheet — usually a washer, then a mounting nut. Hand-tighten these first, then use your wrench to snug them down. Do not over-tighten; you only need them tight enough that the faucet does not move.
Connect the hot and cold water supply lines to the faucet inlets. The lines are usually color-coded (red for hot, blue for cold) or labeled on the faucet itself. Hand-tighten the connection nuts first, then use your wrench to turn them clockwise until they are snug. Again, do not over-tighten — hand-tight plus a quarter turn with the wrench is usually enough.
Turn the water shut-off valves back on by turning them counterclockwise. Open the kitchen faucet slowly and let water run for 10 to 15 seconds to flush out any debris from the lines. Check all connection points under the sink for drips. If you see water dripping, turn off the water again and tighten that connection a bit more with your wrench.
Test the Faucet and Check for Leaks
Turn on the faucet at full hot and full cold to make sure both sides work. Check the spray function if your faucet has one. Look under the sink again while the water is running to confirm there are no leaks at the supply line connections or at the base of the faucet where it enters the sink.
If you see a small drip, turn off the water and tighten that connection slightly. If water is pooling or spraying, turn off the water when ready and check that the connection nut is seated properly — sometimes a small piece of debris prevents a tight seal. Disconnect, clean the threads, and reconnect.
Once everything runs without leaks, wipe up any water under the sink and dispose of the old faucet. Keep the Delta instruction sheet in a drawer for future reference.
Frequently Asked Questions
What if the water shut-off valves under my sink are stuck or broken?
If the valves will not turn, do not force them — you risk breaking them further. You will need to shut off the main water supply to your house instead. This is usually a valve near your water meter or where the main line enters your home. If you cannot locate it, call your water company; they can show you where it is. Once the main is off, you can proceed with the faucet replacement.
Can I replace a Delta faucet if my sink has only two holes instead of three?
Yes. If your new faucet needs three holes but your sink has only two, Delta sells a deck plate (also called an escutcheon) that covers the extra hole. It comes in various finishes to match your faucet. Check the box your faucet came in or contact Delta customer service with your faucet model number to order the correct plate.
My new faucet is leaking from the base where it meets the sink — what went wrong?
The gasket under the faucet is not sealing properly. Turn off the water, loosen the mounting nuts, and lift the faucet slightly. Check that the rubber gasket is centered and not twisted. If it looks damaged, replace it with a new one (Delta sells these separately). Reseat the faucet and tighten the nuts again.
Do I need to use plumber's tape on the water supply line connections?
Most modern Delta faucets and supply lines use compression fittings that do not require tape. If your connection is leaking after you have tightened it, turn off the water, disconnect the line, wrap the male threads with plumber's tape (also called PTFE tape), and reconnect. Wrap clockwise three times around the threads.
How do I know if my new Delta faucet will fit my existing sink?
Check the product specifications on the Delta box or website for the number of holes required and the hole spacing. Measure the distance between your sink holes with a ruler or tape measure. If the spacing matches, the faucet will fit. If you are unsure, contact Delta with your faucet model number and sink hole count — they can confirm compatibility.