Yes, you can replace your kitchen drain yourself, and it is often a manageable DIY task with the right preparation and tools. This guide will walk you through the whole process, from taking out the old drain to sealing under kitchen sink drain fittings correctly.
Gathering Your Supplies: Tools Needed for Sink Drain Replacement
Before starting any job, you need the right gear. Having all your tools needed for sink drain replacement ready saves time and frustration later. Think of this step as laying the groundwork for success.
Here is a list of items you should gather:
- New sink drain assembly (This includes the strainer body, locknut, and gaskets)
- Plumber’s putty or silicone caulk (for installing a basket strainer in kitchen sink)
- Adjustable wrench or basin wrench
- Pliers (channel-lock type work well)
- Screwdriver (Phillips and flathead)
- Bucket or small tub
- Rags or old towels
- Safety glasses
- Putty knife or scraper
- Teflon tape (pipe thread tape)
If you are also dealing with replacing P-trap under kitchen sink or fixing a leaky kitchen drain pipe, you might need new PVC fittings, slip-joint washers, and pipe cutters.
Phase 1: Removing the Old Kitchen Drain Assembly
The first major step is taking out the old unit. This is often messy, so preparation is key.
Shutting Off Water and Preparing the Area
- Turn Off the Water Supply: Look under the sink for the two shut-off valves (hot and cold). Turn both clockwise until they stop.
- Release Pressure: Open the faucet to let any remaining water drain out.
- Place Protection: Put your bucket directly under the P-trap and surrounding pipes. Lay down rags to catch spills.
Disconnecting the Drain Lines
If you have a garbage disposal, you will need to address that connection first.
Removing a Garbage Disposal Flange
If your sink has a disposal, the drain assembly connects through the replacing garbage disposal flange.
- Disconnect Disposal: Follow the manufacturer’s instructions to detach the disposal unit from the mounting ring under the sink. Usually, this involves twisting the disposal body counter-clockwise and letting it hang by its electrical cord or support arm. Caution: Disposals are heavy.
- Unscrew the Locknut: Locate the large ring or locknut that holds the old strainer body to the sink flange from underneath. Use your large pliers or basin wrench to loosen this nut. Turn it counter-clockwise.
- Remove the Old Strainer: Once the nut is loose, the old strainer body should drop down easily. If it sticks, you may need to gently tap the top flange from above.
Disconnecting a Standard Sink Drain (No Disposal)
If you have a standard drain (basket strainer), the process is simpler.
- Disconnect P-Trap: The P-trap is the U-shaped pipe. Place the bucket underneath. Loosen the slip nuts connecting the trap to the tailpiece (the pipe coming down from the sink) and the trap to the drain arm going into the wall. Use your hands first, then channel-lock pliers if needed. Let the water drain into the bucket.
- Remove Tailpiece: Once the trap is off, you can unscrew the tailpiece from the bottom of the old strainer body.
Taking Out the Old Strainer
With the pipes disconnected underneath, focus on the sink basin itself.
- Clean Old Sealant: Use a putty knife to scrape away all old plumber’s putty or caulk from the top rim of the sink opening. Make sure the area is perfectly clean and dry. This is vital for a good seal when repairing a kitchen drain.
Phase 2: Installing the New Basket Strainer (Drain Body)
This part requires precision, especially when installing a basket strainer in kitchen sink.
Preparing the New Strainer Body
- Apply Plumber’s Putty: Roll a rope of plumber’s putty, about half an inch thick, and press it firmly around the underside lip of the new strainer flange (the top part that sits in the sink). Do not use silicone caulk if the directions specifically call for putty, or vice versa.
- Insert the Strainer: Drop the strainer body down into the drain hole from above the sink. Press firmly to seat the putty. Excess putty will squeeze out—that’s normal.
Securing the Strainer from Below
Now move back under the sink.
- Install the Gasket: Slide the large rubber gasket (or friction washer) up onto the threaded tailpiece of the strainer body.
- Thread the Locknut: Screw the large locknut onto the threads of the strainer body from underneath. Hand-tighten it first.
- Tighten the Locknut: Use your basin wrench or large pliers to tighten the locknut firmly. You need it tight enough to compress the putty and seal the unit, but do not over-tighten, as this can crack the sink basin, especially if it is porcelain or ceramic.
- Clean Up Excess Putty: Go back up top. Wipe away the excess putty that squeezed out around the strainer edge using a clean rag or your finger.
Special Note for Garbage Disposals: Replacing Garbage Disposal Flange
If you are replacing garbage disposal flange, the process is similar, but you substitute the basket strainer for the disposal mounting assembly.
- Apply plumber’s putty to the underside of the new flange.
- Insert the flange from above.
- From below, attach the mounting components (the mounting ring and snap ring) onto the flange threads.
- Tighten the mounting screws on the ring evenly until the assembly is secure and the putty seals.
Phase 3: Reattaching the Drain Piping
This phase focuses on how to install a new sink drain assembly components like the tailpiece and P-trap.
Attaching the Tailpiece
The tailpiece connects the new strainer body to the rest of the drain system.
- Apply Thread Tape: Wrap the threads of the tailpiece connection (the lower end) with two or three layers of Teflon tape. This helps prevent leaks where pipes connect.
- Connect to Strainer: Screw the tailpiece onto the bottom of the new strainer body. Hand-tighten, then give it a slight snug with pliers if needed. Remember, the connection is made tighter by the slip nut and washer, not just the threads.
Replacing P-trap Under Kitchen Sink (If Necessary)
If your old P-trap was damaged or you are doing a full kitchen drain repair, now is the time to install the new one.
- Install Washers: Place the new slip-joint washers onto the ends of the P-trap sections. Ensure the tapered end faces the joint it is sealing against.
- Assemble the Trap: Connect the P-trap sections together. Hand-tighten the slip nuts.
- Connecting Kitchen Sink Drain to Waste Line: Align the open end of the P-trap with the drain arm leading into the wall stub.
- Final Tightening: Tighten all slip nuts firmly by hand. Avoid excessive force, as plastic nuts can crack easily. They only need to be tight enough to compress the rubber washers for a seal.
Dealing with Double Sinks
If you have a double sink, you must connect the two tailpieces using a sanitary tee fitting. Ensure the sweep (the smooth curve) of the tee points downwards toward the P-trap connection to allow for smooth flow and prevent clogs. Use Teflon tape and new washers on all connections here.
Phase 4: Testing for Leaks
This is the most crucial step to confirm a successful kitchen sink drain repair.
The Water Test
- Plug the Sink: Put the stopper or strainer basket in place.
- Fill the Basin: Fill the sink basin halfway or more with water.
- Initial Observation (Dry Test): Look closely at the strainer connection before pulling the plug. If water seeps out around the top rim immediately, the plumber’s putty seal failed, and you need to remove the strainer and reapply putty.
- Release Water: Pull the plug and let the water rush down the drain.
- Inspect All Joints: Watch every connection point underneath the sink—the tailpiece connection, the P-trap joints, and where the drain arm enters the wall. Shine a flashlight on every nut.
- Troubleshooting Leaks:
- Leak at a Slip Nut: If water drips from a joint with a slip nut, slightly tighten the nut (a quarter turn at a time) and retest. If tightening does not work, the washer inside might be misaligned or damaged. You will need to take that section apart and correct the washer placement.
- Leak at Strainer Body: If water leaks where the new drain meets the sink bowl, the putty seal failed. Remove the drain, clean off all old putty, reapply fresh putty, and reinstall, ensuring even pressure.
Addressing Disposal Connections
If you have a disposal, run a small amount of water down that side while the disposal is off. Check the mounting ring attachment point carefully for any weeping or dripping. If it leaks, tighten the mounting screws slightly.
Maintenance and Future Considerations
Proper installation leads to fewer issues later. Regular maintenance keeps your new drain running smoothly and prevents the need for repeated fixing a leaky kitchen drain pipe.
Maintaining the New Assembly
- Avoid Harsh Chemicals: Use gentle cleaners. Harsh drain cleaners can damage the rubber gaskets and putty over time.
- Scrape Regularly: If you frequently grind food scraps, occasionally run hot water and baking soda down the drain to keep the pipes clean.
- Check Connections Annually: Once a year, look under the sink and give the slip nuts a slight hand-tightening, just to ensure the rubber gaskets haven’t dried out and loosened their grip.
When to Call a Professional
While this is a great DIY project, some situations warrant a professional plumber:
- Wall or Floor Connection Issues: If the leak is deep inside the pipe entering the wall or floor, it suggests deeper plumbing issues that need specialized tools.
- Corroded Metal Pipes: If you are working with old, corroded brass or galvanized steel drain lines, they might break when you try to loosen them.
- Complex Disposal Wiring: If you need to replace electrical components on the disposal, it is best to hire a licensed electrician or plumber familiar with appliance wiring.
Financial Aspect: Kitchen Drain Replacement Cost
The kitchen drain replacement cost varies widely based on whether you do it yourself (DIY) or hire a professional.
| Component Replaced | Typical DIY Cost (Parts Only) | Typical Professional Cost (Parts & Labor) |
|---|---|---|
| Basket Strainer Only | \$15 – \$40 | \$150 – \$350 |
| P-Trap and Tailpiece | \$10 – \$30 | \$180 – \$400 |
| Full Drain Assembly & P-Trap | \$30 – \$60 | \$250 – \$500+ |
| Garbage Disposal Flange | \$20 – \$50 | \$200 – \$450 |
Note: These are estimates. Prices increase significantly if the job requires opening walls or replacing main drain lines.
If you are only replacing a simple basket strainer and P-trap, the DIY route keeps the kitchen drain replacement cost very low. If you factor in the time and potential need for professional help later due to improper sealing, hiring a pro might be worthwhile for complex situations.
Deciphering Plumbing Codes and Parts
Plumbing systems must adhere to local building codes. While small repairs like replacing P-trap under kitchen sink often don’t require inspections, major remodels or connections to the main line might.
PVC vs. ABS Plastic
Most modern residential drains use PVC (white plastic) or ABS (black plastic). When connecting kitchen sink drain to waste line, ensure you use the same material or appropriate transition fittings if mixing materials. PVC is easier to work with and is more common today.
The Importance of the Washer
The slip-joint washer is the hero of drain connections. It is a tapered ring that compresses when the slip nut is tightened. If you see water dripping, always suspect the washer first:
- Is it present?
- Is it correctly oriented (tapered end toward the nut)?
- Is it old, cracked, or flattened?
If the washer looks suspect, replace it, even if you are only performing a simple kitchen sink drain repair.
Final Review: Completing the Job
After successfully testing and confirming no leaks, you can clean up your workspace. Store your tools, dispose of the old parts, and enjoy your leak-free sink. You have successfully navigated replacing your drain, which includes steps for replacing garbage disposal flange, how to install a new sink drain assembly, and fixing a leaky kitchen drain pipe if needed.
Frequently Asked Questions (FAQ)
How tight should I make the connection when sealing under kitchen sink drain pipes?
You should tighten slip nuts and locknuts until the rubber or friction washers are visibly compressed and water stops leaking during a test. For plastic nuts, hand-tight plus a slight turn with pliers is usually enough. Over-tightening plastic can crack the fitting, causing a leak worse than the original problem.
Can I use silicone caulk instead of plumber’s putty for installing a basket strainer in kitchen sink?
Yes, many modern drain assemblies include instructions allowing for silicone caulk instead of plumber’s putty. Silicone creates a stronger, longer-lasting waterproof seal and is often better if the sink material is natural stone (like granite), which putty can sometimes stain. Always follow the instructions provided with your new drain kit.
What is the difference between a tailpiece and a P-trap?
The tailpiece is the straight pipe section that connects directly to the underside of the sink drain strainer body. The P-trap is the U-shaped bend in the pipe immediately following the tailpiece. The P-trap’s job is to hold a small amount of water to create a seal that blocks sewer gases from coming up through the drain.
Do I need to disassemble the whole drain system when fixing a leaky kitchen drain pipe?
If the leak is minor (e.g., a loose washer), you might only need to tighten that specific joint. However, if the leak is coming from the main connection point under the strainer or if the P-trap is cracked, you will need to take apart that section to properly clean the threads and replace the seals or fittings, making it a partial or full kitchen drain repair.
Is connecting kitchen sink drain to waste line difficult if the new drain height is different?
Yes, this is a common issue. If the new drain assembly sits higher or lower than the old one, you may need to adjust the height of the tailpiece (by cutting it if it’s PVC) or modify the P-trap configuration using extra fittings (like an extension piece or an adjustable elbow) to ensure a proper slope and connection into the wall pipe.