When you hear water dripping from under the kitchen sink when it’s full of water, you’re most likely dealing with a broken sink drain flange. The flange is a flat collar that sits at the bottom of the sink, usually with a strainer-like grid attached to it. Most kitchen sink flanges are made of metal and can corrode over time. So, how to remove and replace it?
To remove the sink drain flange, you must loosen the nuts that hold the drain tailpiece and the P-trap, then unscrew the drain flange from the tailpiece. If it is trapped due to hardened putty or silicone, you may have to use a pair of pliers to loosen it.
The Sink Drain Flange
The strainer-like grid designed to trap food waste is the main difference between a kitchen sink drain flange and a bathroom sink flange. However, there are various types of flanges you can find on kitchen sinks. Here’s how they differ from one another.
Standard kitchen sink flanges
These are the simplest flanges, consisting of a flat collar with a grid covering the drain. This flange type is uncomplicated and inexpensive. Most models are made of metal, although you can now find drain flanges made of plastic and coated with a polished finish.
Removing and replacing standard flanges is as simple as it gets. The main disadvantage is that food chunks can still find their way through the strain holes and clog the P-trap or drain pipe.
Flanges with strainer and basket
More performing than the standard type, these flanges have a small basket placed between the strainer and the drain. The basket catches food waste while letting the water pass through, preventing clogs. The strain and basket assembly are easy to remove and clean when needed.
Like the standard flanges, these are generally made of metal or plastic and are available in multiple finishes.
Drains with garbage disposal
Flanges with a garbage disposal are the best you can find. They don’t have a basket, allowing you to flush food waste down the drain. This waste ends up in a disposer installed under the sink, between the flange and the P-trap.
The flange doesn’t come with the disposer, so installing compatible parts is essential if you want this setup under the kitchen sink.
Most kitchen sink flanges have a standard size of 3-1/2 inches in diameter. This feature makes it easy to replace the flange when needed or switch from one flange type to another.
Why is Your Sink Drain Flange Stuck?
While changing a sink drain flange isn’t complicated, loosening a stuck flange can be time-consuming. Here are some of the reasons why your sink’s flange is stuck.
Flanges are usually threaded onto the drainpipe, but some plumbers may use putty to reinforce them. Putty can harden over time, creating a tight bond between the flange and the sink. You should be able to remove it with a pair of pliers.
Food seeped into the threads
Sometimes, a threaded flange may become slightly loose, and food waste could get into the threads. In time, waste can build up on the threads and stick to the flange.
Scale or rust damage
Like food waste, water can seep beneath the flange and into the threads. Water deposits can damage the metal, causing it to rust. Similarly, hard water can lead to scale deposits on the threads. In both cases, the flange may become stuck.
Tools Required for Removing Sink Flange
Removing a sink flange is easy, even though you might need some elbow grease if the flange is stuck. Here are the tools and materials you’ll need for the job.
- Penetrating lubricant
- Putty knife
- 10-inch tongue-and-groove pliers
- 16-inch tongue-and-groove pliers
- Pipe wrench
- Rubber gloves
How to Remove a Stuck Kitchen Sink Drain Flange (3 Easy Steps)
Removing a kitchen sink drain flange is easy, even if it is stuck. Follow the three easy steps below.
Step 1 – Prepare the work area
Before starting, clear the area below the sink of any stored items; this will give you ample space to move. If your kitchen sink has one, turn off the garbage disposer and shut off the main water valve. Although turning off the water is not necessary when removing or changing the drain flange, it will limit accidents.
Step 2 – Loosen the drainpipe
Use a flashlight to illuminate the plumbing beneath the sink and loosen the drainpipe with a pipe wrench.
Spray penetrating lubricant onto the threads on the bottom of the flange underneath the sink and let it soak in for the amount of time indicated by the manufacturer.
After the time has passed, keep the pipe still with the pipe wrench and use the 10-inch tongue-and-groove pliers to turn the coupling connecting the pipe to the flange counterclockwise to loosen it.
If the flange turns with your movement instead of loosening, try inserting the pliers’ handles into the drain and open the flange from above. When open, carefully remove the drainpipe from the flange.
Step 3 – Unfasten and remove the flange
The flange is connected to the sink with nuts (older models may use nuts and bolts). To remove it, use the 16-inch tongue-and-groove pliers and turn it counterclockwise. If it doesn’t move, spray penetrating lubricant onto the nut and let it soak into the thread before trying again.
Some plumbers fix the flanges with plumber’s putty. If yours is fixed with putty and stuck, you should also use a putty knife to remove as much hardened putty as possible before unscrewing the flange.
If it still doesn’t move, tap the flange’s edge under the kitchen sink with a hammer. This action should raise the flange enough to loosen the grip. Once unfastened, the flange should be easy to lift from the sink, but you can use a pair of pliers to pull out a particularly stubborn flange.
How to Remove a Kitchen Sink Strainer?
Kitchen sink flanges with a strainer basket are also easy to remove, but a few extra steps are needed. Start with clearing the area beneath the sink, then follow the steps below.
Step 1 – Remove the drain pipe tailpiece
Use a wrench and pliers to remove the drainpipe from the flange. Once the nut is loose, unscrew by hand and remove the drain from the strainer.
Step 2 – Remove the strainer lock nut
Kitchen sink strainers are fixed with lock nuts that are usually fastened with the help of a special wrench. Use the wrench that came with your strainer to unfasten the locknut by turning it counterclockwise. Alternatively, you can use a pair of needle-nose pliers.
Insert the pliers’ nose into the strain opening and turn the locknut. Once it’s loose, unscrew it by hand and remove the tailpiece and nylon washer.
Step 3 – Remove the drain flange
Follow the steps explained above to remove the drain flange from the sink. If a hardened plumber’s putty blocks it, use a putty knife and a hammer to loosen it, then use a pair of pliers to pull it out when it’s loose.
You can now decide whether to install a new strainer or reuse the existing one. Inspect the strainer you took out for damage; if you didn’t notice any flaws, the leak could have been caused by cracks in the putty. Clean the hardened putty, then apply new putty and install the strainer back in place.
5 Tips to Avoid Kitchen Sink Drain Flange Blockage
A stuck flange can be frustrating to remove if leaks happen, but there are ways to prevent it from getting stuck in the first place. Here are some tips and tricks:
1. Seal the flange with silicone instead of putty
The plumber’s putty creates a tight seal that prevents leaks, but it can harden in time and become a sort of cement. Silicone also provides a watertight seal, but it is easier to remove than putty. The only problem with silicone is that it can get yellow in time, and mold and mildew can grow under it, so you might have to change it every few years. You could also replace the putty with a rubber gasket or seal.
2. Avoid flushing coffee grounds down the drain
Coffee grounds can find their way easily into the thread and accumulate, blocking the flange from turning when you want to unscrew it. Moreover, coffee grounds can clog your entire plumbing system, so you should dispose of them in the trash.
3. Don’t dispose of grease and oil in the kitchen sink
Liquids can also find their way into the thread. Grease and oil can accumulate and, combined with ordinary household cleaners, can turn into soap. Not only will the soap block the flange, but it can also cause blockages down the pipe. You should never flush grease and oil down the drain or in the toilet.
4. Seal the flange underneath the sink, too
Most plumbers don’t seal the connection between the tailpiece and drain pipe. Sealing isn’t necessary as long as the pieces are well secured with couplers. The only issue is that moisture can find its way into the thread from underneath, too, causing a metal thread to rust. Rust can block the drain flange, making it hard to remove.
5. Apply plumber’s grease on the threads before installing the flange
Lastly, a thin layer of plumber’s grease applied onto the thread before installing the drain flange can prevent it from getting stuck over time.
FAQs: Sink Drain Flange
Can I use plumbers putty on plastic flanges?
No, it is not recommended to use plumber’s putty on plastic flanges because it can attack the flange’s plating and cause it to come off. Plastic flanges usually come with rubber gaskets designed to replace the putty.
How to remove a stuck sink drain nut?
Sometimes, the reason why you can’t remove the drain flange is because of a stuck nut. Here’s how to remove it:
- Use a pair of slip-joint pliers to grip the sides of the nut and turn it counterclockwise. Try to hold the pliers as firm as possible as you turn to increase force.
- Once you’ve attempted to turn the nut, spray some penetrating lubricant onto it and wait for the time instructed on the product.
- Grip the nut again with the pliers and turn counterclockwise first, then clockwise to loosen it. If it still doesn’t move, applying heat might help.
- Turn a hairdryer on the hottest setting and direct the hot air onto the nut. Let it warm the nut for several minutes, then use the pliers and turn the nut. If it doesn’t budge, tap with a hammer, then apply heat and turn it.
- If this doesn’t work, the only way to remove the drain nut is by breaking it off with the pliers and a hammer. You’ll need a new nut to fix the flange back into its place once you’ve fixed the leak.
Removing a stuck drain flange is easy, but the process could require some force. Nevertheless, most homeowners should be able to fix a flange leak by themselves.
Have you ever dealt with leaking drain flanges before? How did you remove them? Share your thoughts, tips, and tricks in a comment below.