The flange comes out by loosening the mounting ring underneath the sink

The flange is the metal or rubber ring that sits on top of your sink drain opening and holds the garbage disposal in place. To remove it, you work from underneath the sink, not from above. You will loosen the mounting ring (a large nut that threads onto the flange shaft) by turning it counterclockwise with a wrench or pliers, then push the flange up and out from the top. The whole job takes 10 to 20 minutes if the mounting ring is not stuck.

Before you start, turn off the power to the disposal at the circuit breaker and make sure the unit is not running. If you are removing the flange because the disposal is broken or you are replacing it, you do not need to turn the disposal on again — just kill the power and leave it off.

Key Takeaways

  • The mounting ring underneath the sink holds the flange in place; loosen it by turning counterclockwise with a wrench or adjustable pliers.
  • You may need to remove the disposal unit itself first if it is bolted to the flange, which takes an extra 5 to 10 minutes.
  • If the mounting ring will not turn, explore penetrating oil and wait 15 to 30 minutes before trying again.
  • Once the ring is loose, push the flange up from below and it will slide out of the sink opening from the top.
  • Scrape away old plumber's putty or rubber gasket material from the sink opening before installing a new flange.

What you need before you start

Gather an adjustable wrench or a pair of locking pliers (Vise-Grips work well), a flashlight, and a bucket or towel to catch water that may drip from the drain. If the mounting ring is stuck, you will also want penetrating oil such as WD-40 or a similar product.

You do not need special tools. A standard adjustable wrench fits the mounting ring on most disposals. If you do not have one, locking pliers will grip the ring just as well. The flashlight matters because the space under the sink is dark and you need to see what you are turning.

Disconnect the disposal unit if it is bolted to the flange

Some disposal units bolt directly to the flange from underneath. If yours does, you will see three or four bolts around the flange shaft. Loosen these bolts first by turning them counterclockwise with a wrench. You do not have to remove them completely — just loosen them enough that the disposal unit hangs freely and is no longer clamped to the flange.

Once the bolts are loose, the disposal may drop slightly. Support it with one hand or prop it up with a block of wood so it does not fall and damage the drain line. Then move on to loosening the mounting ring.

Loosen the mounting ring from underneath

Slide under the sink with your flashlight and look up at the drain opening. You will see a large ring (usually 3 to 4 inches across) threaded onto the flange shaft. This is the mounting ring. Place your wrench or pliers on the ring and turn it counterclockwise. Turn slowly and steadily — do not jerk or force it.

The ring should turn freely if it is not corroded. If it will not budge after a few tries, stop and spray penetrating oil around the threads where the ring meets the flange. Let it soak for 15 to 30 minutes, then try again. Repeat if needed. Once the ring is loose enough to turn by hand, unscrew it the rest of the way and set it aside.

Push the flange up and out from the top

Once the mounting ring is off, go to the top of the sink and look down into the drain opening. The flange should now be loose. Push it up from underneath (you may need to use your hand or a block of wood to explore upward pressure) and it will slide out of the opening. If it resists, check that the mounting ring is fully off and that you have loosened any bolts holding the disposal to the flange.

The flange may have a rubber gasket or old plumber's putty stuck to the underside of the sink. This is normal. Once the flange is out, scrape away all the old gasket material and putty from the sink opening using a putty knife or old credit card. Wipe the opening clean with a damp cloth so it is ready for a new flange if you are installing one.

What to do if the mounting ring is stuck

A stuck mounting ring is the most common delay. Corrosion, mineral buildup, or old plumber's putty can lock it in place. Spray penetrating oil generously around the threads and let it sit for at least 15 minutes. You can also try tapping the ring gently with a hammer to break the corrosion loose, then spray again and wait.

If the ring still will not turn after two or three attempts, you have another option: cut the flange out. Use a rotary tool with a cutting disc or a hacksaw to cut through the flange shaft just below the mounting ring. Once the shaft is cut, the ring will come free and you can remove the flange. This method takes longer but works when the ring is truly seized.

Cleaning the sink opening after removal

Once the flange is out, the drain opening will have old sealant around it. Use a putty knife, scraper, or even an old credit card to scrape away all the plumber's putty, rubber gasket, or caulk. Work carefully so you do not scratch the sink itself. Wipe the opening with a damp cloth and let it dry completely before you install a new flange or cap the drain.

If you are not installing a new disposal or flange, you can cover the opening with a straightforward drain cap (a rubber or plastic plug that costs a few dollars) or have a plumber install a standard drain strainer. Do not leave the opening uncovered because debris and odors will come up through it.

Frequently Asked Questions

Do I have to remove the whole disposal to get the flange out?

Not always. If the disposal bolts to the flange, you only need to loosen those bolts enough to free the disposal from the flange itself. The disposal can then hang from the drain line while you work on the flange. If the disposal is glued or sealed to the flange, you may have to remove it completely.

What if water leaks from under the sink while I am working?

Place a bucket or towel under the drain before you start. The water is usually just what is sitting in the trap below the sink. Once the flange is out, the water will drain. If water keeps coming, check that the trap is not clogged and that you have not accidentally loosened the connection between the trap and the wall drain.

Can I reuse the old flange?

You can reuse it if it is not cracked, corroded, or bent. Clean it thoroughly and inspect it for damage. If you are replacing the disposal, it is often cheaper and safer to buy a new flange kit that matches your new disposal model, because flanges are not expensive and a poor fit can cause leaks.

How long does this job usually take?

If the mounting ring turns freely, 10 to 20 minutes. If it is stuck and you have to soak it with penetrating oil, add 30 to 45 minutes of waiting time. If you have to cut the flange out, add another 15 to 30 minutes depending on the tool you use.

What should I do with the old flange after I remove it?

If it is metal, you can recycle it at a local metal recycling center. If it is plastic or rubber, throw it in the trash. Do not pour any old plumber's putty down the drain — scrape it into the trash instead.