The flange comes out by unbolting it from underneath the sink
The flange is the ring that sits on top of your sink opening, where the garbage disposal connects. To remove it, you work from under the sink: unbolt the mounting ring that holds the flange in place, then push the flange up and out from above. The whole job takes 15 to 30 minutes if the bolts turn freely, longer if they are stuck.
You will need a flashlight, an adjustable wrench or socket set, and possibly penetrating oil if bolts have not moved in years. Have a bucket or towel ready—old plumber's putty or caulk will fall when you loosen things. If the disposal is still attached, you must disconnect it first.
Key Takeaways
- Turn off power to the disposal at the breaker and test that it is dead before you touch anything underneath.
- The mounting ring bolts are accessed from below the sink and must be loosened in a cross pattern, like removing a wheel, to avoid warping the flange.
- Old plumber's putty will crumble and fall—place a bucket under the sink before you start loosening bolts.
- If bolts will not turn after 10 minutes of steady pressure, spray them with penetrating oil, wait 15 minutes, and try again rather than forcing them.
Turn off power and disconnect the disposal first
Before you touch anything, turn off the breaker that controls the garbage disposal. Go to your electrical panel and flip the switch all the way off. Then go back to the sink and try to turn on the disposal—nothing should happen. This is the only safe way to work.
If the disposal is still bolted to the flange, you need to unbolt it from the flange first. Look at the three bolts that hold the disposal to the mounting ring (the ring that hangs from the flange). Loosen these three bolts with a wrench, working in a cross pattern—loosen one, then the one across from it, then the third—so the disposal comes down evenly. Once all three are loose enough, the disposal will drop into your hands. Set it aside on a towel.
Locate and loosen the mounting ring bolts
Shine a flashlight under the sink and look up at the flange. You will see a metal ring bolted to the underside of the flange with three bolts. This is the mounting ring. These three bolts are what hold the entire flange in place.
Using an adjustable wrench or a socket wrench, loosen each bolt in a cross pattern—loosen one bolt a quarter turn, then the one across from it a quarter turn, then the third a quarter turn. Repeat this pattern until all three bolts are loose enough to turn by hand. Do not remove them completely yet; just loosen them enough that you can turn them with your fingers.
The reason for the cross pattern is to avoid warping the flange. If you loosen one bolt all the way while the others are tight, the flange will bend and may crack or stick. Going in a cross pattern keeps the pressure even.
Push the flange up and out from above
Once all three bolts are hand-loose, go to the top of the sink. Place your hands on the flange ring and push it straight up. It should move. Keep pushing until the flange clears the sink opening and you can lift it out completely.
As you push up, old plumber's putty or caulk that sealed the flange to the sink will crumble and fall. This is normal. If you placed a bucket under the sink, the debris will fall into it. If not, it will land on whatever is below—usually pipes or the cabinet floor.
What to do if bolts are stuck or corroded
If a bolt will not turn after steady pressure with a wrench, do not force it. Forcing a stuck bolt can snap it, and then you have a broken bolt stuck in the hole—a much bigger problem. Instead, spray the bolt with penetrating oil (such as WD-40 or similar products). Spray it generously and let it soak for 15 to 20 minutes.
After the oil has soaked, try again with the wrench. Use slow, steady pressure rather than jerking motions. If it still will not move after another 10 minutes of trying, spray it again and wait another 15 minutes. Patience works better than force on corroded bolts.
If a bolt breaks or you cannot get it to move at all, you may need to call a plumber. They have tools like bolt extractors that can remove a broken bolt without damaging the mounting ring.
Clean the sink opening before installing a new flange
Once the flange is out, you will see the sink opening and the underside of the sink rim. Old plumber's putty will be stuck to both surfaces. Scrape it off with a putty knife or old credit card, working carefully so you do not scratch the sink. Get the surface as clean and dry as you can.
If you are installing a new flange, the sink opening must be clean and dry for the new putty or caulk to seal properly. If you are reusing the old flange, clean it the same way before you reinstall it.
Frequently Asked Questions
Can I remove the flange without taking out the disposal?
No. The disposal is bolted to the mounting ring, which is bolted to the flange. You must unbolt the disposal first, or the mounting ring will not come loose. Once the disposal is unbolted and set aside, the mounting ring bolts are accessible from underneath.
What if I cannot reach the mounting ring bolts from under the sink?
The bolts are always underneath the sink, but if your cabinet is very full or the space is tight, you may need to remove items stored below the sink first. A headlamp or flashlight on a band around your head frees up both hands. If the space is genuinely too tight, a plumber can access it from a different angle or use specialized tools.
Do I need to replace the plumber's putty when I reinstall the flange?
Yes. Old putty loses its seal over time and becomes hard and crumbly. When you reinstall the flange, scrape off all the old putty, clean the surfaces, and explore a fresh bead of plumber's putty or silicone caulk around the underside of the flange before you bolt it back down.
How tight should the mounting ring bolts be?
Snug, but not so tight that you strain with the wrench. Hand-tight plus a quarter turn with the wrench is the right amount. Over-tightening can crack the flange or strip the bolt threads. You want the flange to sit flat and not move, not to be crushed into place.