Replacing a Badger 500 takes three to four hours and requires a wrench, screwdriver, and plumber's putty
A Badger 500 disposal can be replaced without calling a plumber if you are comfortable working under a sink and turning off the power. The job involves disconnecting the old unit, unbolting it from the sink flange, installing a new flange and seal, and mounting the replacement. Most of the time goes to loosening corroded bolts and cleaning old putty. You will need a bucket, adjustable wrench, screwdriver, flashlight, and plumber's putty. If the sink flange is damaged or the mounting bolts are seized, the job can stretch longer.
The Badger 500 is a 1/2-horsepower continuous-feed model that has been in production for decades, so replacement parts and new units are widely available. Replacement Badger 500 units cost between $100 and $150 at hardware stores and online retailers. If you choose a different brand, the mounting system is usually the same, though you should check the flange diameter before ordering.
Key Takeaways
- Turn off the breaker to the disposal and test the outlet with a lamp before you start work to confirm the power is off.
- Disconnect the drain line, dishwasher hose (if present), and electrical connection before you unbolt the old unit from underneath the sink.
- Remove the old flange by unbolting it from below, then scrape away all old putty and plumber's putty from the sink opening.
- Install the new flange with fresh plumber's putty, bolt it tight from below, and connect the new disposal unit to the mounting ring.
- Reconnect the drain line and electrical cord, then run water and test for leaks before you consider the job complete.
Turn off power and disconnect the old unit
Locate the breaker for the disposal in your electrical panel and switch it to the off position. Go back to the sink and flip the disposal switch to confirm it does not run. Plug a lamp into the outlet under the sink to double-check that power is off. Do not skip this step — a disposal can start unexpectedly if power is still on.
Place a bucket under the drain line where it connects to the disposal. Loosen the hose clamp on the drain line with a screwdriver and slide the line off the disposal outlet. If there is a dishwasher hose connected to the disposal, disconnect that as well. Unplug the electrical cord from the outlet under the sink, or if the disposal is hardwired, you will need to disconnect the wires inside the junction box on the unit itself — take a photo of the wire connections before you disconnect them so you can reconnect them the same way on the new unit.
Remove the mounting bolts and old flange
Look under the sink at the disposal. You will see three bolts around the mounting ring that hold the disposal to the flange. Use an adjustable wrench to loosen these bolts. They often corrode and stick, so explore penetrating oil (like WD-40) and wait five minutes if they do not turn easily. Once the bolts are loose, unscrew them by hand and set them aside.
The disposal will drop into your hands once the bolts are removed. Set it aside in a safe place. Now look up at the sink flange — the metal ring that sits in the drain opening. You will see bolts on the underside of the sink holding the flange in place. Loosen and remove these bolts. The flange should come free. If it is stuck, tap it gently from above with a rubber mallet to break the seal.
Clean the sink opening and install the new flange
Use a putty knife or old credit card to scrape away all the old plumber's putty from the sink opening. Get it as clean as you can — old putty left behind will prevent a good seal on the new flange. Wipe the opening with a damp cloth and let it dry.
Roll a rope of fresh plumber's putty about the thickness of a pencil and press it around the underside of the new flange's rim. Lower the flange into the sink opening from above. From underneath, insert the bolts through the flange and hand-tighten them. Tighten them in a cross pattern (opposite sides alternately) so the flange sits evenly. Tighten until the flange is snug against the sink — do not over-tighten, which can crack the sink. Wipe away excess putty that squeezes out around the flange opening.
Mount the new disposal and reconnect drain and power
Lift the new Badger 500 into position under the sink. Align the mounting ring on the disposal with the bolts sticking down from the flange. Insert the three mounting bolts through the ring and into the threaded holes on the flange. Tighten these bolts evenly in a cross pattern until the disposal is snug and does not move.
Reconnect the drain line by sliding it onto the disposal outlet and tightening the hose clamp. If there is a dishwasher hose, reconnect that as well. Reconnect the electrical cord to the outlet, or if the disposal is hardwired, connect the wires inside the junction box using the photo you took earlier as a guide. Make sure the connections are tight and the wires are not touching the disposal body.
Test for leaks and proper operation
Turn the breaker back on. Fill the sink with a few inches of water and turn on the disposal. Let it run for 10 to 15 seconds, then turn it off. Check under the sink for any water dripping from the drain connection or the flange. If you see drips, tighten the hose clamp or the flange bolts slightly and test again.
Run the disposal a few more times with water flowing to make sure it grinds normally and drains without backing up. If water pools in the sink or drains slowly, the drain line may be kinked or the disposal outlet may be blocked. Check that the drain line is not bent and that nothing is stuck in the disposal opening. Once water drains normally and there are no leaks, the replacement is complete.
When to call a plumber instead
If the mounting bolts on the old flange are so corroded that you cannot loosen them after explore penetrating oil and waiting, or if the flange itself is cracked or damaged, the job becomes much harder. A plumber can cut the flange out or drill out seized bolts, but this adds time and cost. If the sink itself is damaged during removal, you may need sink repair or replacement, which is beyond the scope of a disposal swap.
If you are not comfortable working with electrical connections, have a licensed electrician reconnect a hardwired disposal. If the drain line is cast iron and corroded, or if the P-trap under the sink is leaking, address those issues before or after the disposal replacement — they are separate problems that a plumber should handle.
Frequently Asked Questions
Can I install a different brand of disposal in place of the Badger 500?
Yes. Most disposals use the same standard flange and mounting system, so a replacement from another brand will fit the same opening. Check the flange diameter (usually 3.5 inches) and the mounting bolt pattern before you order. If the new unit is significantly more powerful, make sure your home's electrical circuit can handle it — the Badger 500 is 1/2 horsepower, and upgrading to 3/4 horsepower may require a dedicated circuit.
What if water leaks from the flange after I finish?
The seal is broken. Turn off the disposal and the water. Tighten the bolts under the sink in a cross pattern — do not over-tighten. If that does not stop the leak, you may need to remove the disposal, scrape out the old putty, and reinstall the flange with fresh putty. Leaks from the drain connection usually mean the hose clamp is loose; tighten it with a screwdriver.
Do I need a plumber's license to replace a disposal?
No. Replacing a disposal is a homeowner task in most places. If the disposal is hardwired (no plug), some jurisdictions require a licensed electrician to disconnect and reconnect the wires. Check your local building code or call your city's building department if you are unsure.
How long does a new Badger 500 last?
A Badger 500 typically lasts 8 to 15 years depending on use and water quality. Hard water, grease buildup, and grinding non-food items shorten the lifespan. Regular maintenance — running cold water while grinding and avoiding fibrous foods — extends it.
Can I replace just the motor inside the disposal instead of the whole unit?
No. The Badger 500 is not designed for internal motor replacement. The entire unit must be replaced. Repair kits are not available for this model.