What You Need Before You Start

A Badger 5 is a 1/2-horsepower continuous-feed disposal made by InSinkErator. Installing one takes about an hour if you already have a disposal in place, or two to three hours if you're starting from scratch with no existing unit. You'll need basic hand tools: an adjustable wrench, a screwdriver (both Phillips and flathead), a flashlight, and a bucket to catch water. Have a towel or old cloth ready—the space under your sink is wet.

Before you buy the unit, check two things. First, look under your sink and see whether you have a dishwasher. If you do, the Badger 5 can connect to it, but you'll need an extra part (a dishwasher inlet kit) that doesn't come in the box. Second, measure the opening in your sink. The Badger 5 fits a standard 3.5-inch sink opening. If your opening is smaller or larger, you may need a different unit or an adapter ring.

Key Takeaways

  • The Badger 5 mounts under the sink using a three-bolt ring system that tightens from below, so you need clearance underneath to work.
  • If you're replacing an old disposal, turn off the power at the breaker and disconnect the old unit completely before starting the new installation.
  • The drain connection uses a rubber gasket and slip nut—hand-tighten first, then use a wrench to snug it, but do not over-tighten or you'll crack the fitting.
  • Once installed, run cold water for 30 seconds before and after grinding to flush the unit and prevent clogs.
  • If the unit hums but doesn't spin, turn it off when ready—something is jammed, and running it will burn out the motor.

Removing the Old Disposal (If You Have One)

Turn off power at the circuit breaker. Flip the switch at the sink to confirm the unit is dead. Unplug the disposal if it has a plug, or if it's hardwired, you'll need to disconnect the wires inside the electrical box under the sink—take a photo first so you remember which wire goes where.

Loosen the three bolts on the mounting ring using an adjustable wrench. Turn them counterclockwise. The unit will drop into your hands—it's heavy, so support it as you work. Once it's loose, disconnect the drain line by loosening the slip nut (the large nut where the disposal connects to the drain pipe). Have your bucket ready; water will spill. Disconnect the dishwasher line if there is one.

Remove the old mounting ring completely. Clean the sink flange (the metal ring that sits in the sink opening) with a cloth to remove old putty or debris. If the flange is damaged or won't tighten, replace it now before installing the new unit.

Installing the Mounting Ring and Gasket

The Badger 5 comes with a rubber gasket, a metal mounting ring, and three bolts. Place the rubber gasket on top of the sink flange, inside the sink. The gasket sits between the sink and the mounting ring to create a watertight seal.

From underneath the sink, slide the mounting ring up through the opening and align it with the three bolt holes. Insert the three bolts through the ring into the threaded holes on the flange. Hand-tighten all three bolts first—do not use a wrench yet. Tighten them evenly in a triangle pattern (one, then the opposite one, then the third) so the ring pulls up straight and the gasket compresses evenly.

Once all three are hand-tight, use your wrench to tighten each bolt another quarter-turn. Stop. The gasket should be compressed but not squeezed so hard that the rubber bulges out. If water leaks from under the sink later, you can tighten these bolts more, but start conservatively.

Connecting the Badger 5 to the Mounting Ring

The Badger 5 has a collar on top that locks onto the mounting ring. Align the three tabs on the collar with the three slots on the mounting ring. Push the unit up and turn it clockwise by hand until it stops. It should be snug but not require a tool to lock in place. If it won't turn, the tabs are not aligned—pull it down and try again.

Once locked, the unit hangs from the mounting ring. Check that it sits level and doesn't tilt. If it does, loosen the mounting bolts slightly, adjust the gasket, and re-tighten.

Connecting the Drain Pipe

The drain outlet on the Badger 5 is a threaded male fitting. Your drain line has a slip nut (a large nut that slides over the fitting). Slide the slip nut onto the outlet, then slide the rubber washer that comes with the unit onto the outlet as well. The washer sits between the nut and the fitting.

Hand-tighten the slip nut onto the outlet. Once it's snug by hand, use your wrench to turn it another half-turn. Do not over-tighten. The rubber washer creates the seal; the nut just holds it in place. If you crank it too hard, you'll crack the plastic fitting and create a leak that's harder to fix than a loose connection.

If you have a dishwasher, the inlet is on the side of the unit. You'll need a dishwasher inlet kit (sold separately) to connect the line. Follow the kit's instructions—it usually involves removing a rubber plug and screwing in an adapter.

Wiring the Unit

The Badger 5 comes with a three-prong plug. If your sink has an outlet under it, plug the unit in. If there is no outlet, or if the old disposal was hardwired, you'll need an electrician to run a dedicated circuit and install an outlet or hardwire the unit to the electrical panel. Do not use an extension cord or plug the disposal into an outlet that also powers other appliances.

If you're replacing an old hardwired unit and the wires are still there, turn off the breaker, remove the cover plate on the electrical box under the sink, and disconnect the old wires. The Badger 5 has a power cord, so you have two options: hire an electrician to install an outlet, or have them hardwire the new unit using wire connectors and conduit. Either way, this is not a DIY step if you're not comfortable working with household electrical wiring.

Testing and First Run

Before you grind anything, run cold water for 30 seconds with the unit off. Check under the sink for leaks at the drain connection and around the mounting ring. If you see water dripping, tighten the slip nut a half-turn and test again.

Once you're sure there are no leaks, turn on the cold water, flip the switch to start the unit, and let it run for a few seconds. Drop in a few ice cubes or a small piece of fruit to test the grinding action. The unit should spin smoothly and grind quietly. Turn it off, let the water run for another 30 seconds to flush, then turn off the water.

If the unit hums but doesn't spin, something is jammed. Turn it off when ready and do not run it again until the jam is cleared. Use tongs or pliers to remove the object—never put your hand down the drain. If you can't reach it, call a plumber.

Frequently Asked Questions

Can I install a Badger 5 if I don't have a sink opening?

No. The Badger 5 requires a standard 3.5-inch opening in the sink basin. If your sink has no opening, you would need to have a plumber cut one, which involves cutting through stainless steel or porcelain and is not a home project.

What if water leaks from under the mounting ring?

The gasket is compressed unevenly or not enough. Turn off the unit and let it drain. Tighten the three mounting bolts a quarter-turn each in a triangle pattern. Test again. If it still leaks, loosen the bolts, pull the unit down, remove the gasket, and check whether it's torn or flattened. Replace it if damaged.

Do I need a plumber to install this?

If you already have a disposal and an outlet under your sink, you can do the swap yourself in about an hour. If you're starting from scratch, have no outlet, or are not comfortable working under the sink, hire a plumber. The cost is usually $150 to $300 for labor.

Can the Badger 5 grind bones or hard objects?

No. The Badger 5 is designed for soft food scraps—vegetable peels, cooked meat, bread, pasta. Bones, pits, shells, and hard objects will jam the unit or damage the grinding ring. Scrape these into the trash before rinsing dishes.

Why does my new Badger 5 smell bad?

Food particles are trapped in the drain line or the unit itself. Run cold water and the unit for 30 seconds, then add a handful of ice cubes and grind them. Follow with another 30 seconds of water. If the smell persists, pour a cup of white vinegar down the drain, let it sit for 15 minutes, then run the unit with cold water for 30 seconds.