How to Replace a Garbage Disposal (DIY Guide)

Replacing a garbage disposal is a manageable DIY project for handy homeowners — most replacements take 1–2 hours. If you're comfortable working under a sink with basic tools and can follow a wiring diagram, you can save $150–$250 in labor by doing it yourself.

This guide walks through the full process: choosing the right replacement, removing the old unit, and installing the new one. If you'd rather hire a pro, we'll cover what that costs too.

When to Replace vs. Repair

Replace your garbage disposal if:

• It leaks from the bottom — this means the internal seals have failed. Seal replacement isn't cost-effective.
• The motor hums but blades won't turn even after using the Allen wrench reset (see our unclogging guide). The motor may be burned out.
• It's over 10 years old and performance has declined
• Frequent resets — if it trips constantly, the motor is failing
• Persistent odor that doesn't go away after deep cleaning

Simple jams, clogs, and reset issues are usually fixable without replacement.

Choosing a Replacement

Horsepower

For most LA households, a 1/2 HP or 3/4 HP unit is the sweet spot. Higher HP units jam less, grind finer, and last longer.

Mounting type

Most disposals use a standard 3-bolt mounting system (EZ Mount). If your current unit uses this system, any 3-bolt disposal will fit without modifying the sink. Check your existing mount before buying.

Tools and Materials

• New garbage disposal
• Plumber's putty
• Screwdriver (flat and Phillips)
• Adjustable pliers or channel locks
• Allen wrench (usually included with new unit)
• Wire nuts (usually included)
• Bucket and towels
• Flashlight

Step-by-Step Replacement

Step 1: Disconnect power

Turn off the circuit breaker that powers the disposal. Verify it's off by flipping the disposal switch — nothing should happen. If the disposal is plugged into an outlet under the sink, simply unplug it.

Step 2: Remove the old disposal

1. Place a bucket under the disposal to catch water.
2. Disconnect the dishwasher drain hose (if connected) by loosening the hose clamp.
3. Disconnect the drain pipe (P-trap connection) by unscrewing the slip nut.
4. Support the disposal with one hand and use the other to turn the lower mounting ring counterclockwise. The unit will drop free — it's heavy (8–15 lbs), so be ready.
5. Disconnect the electrical wires inside the bottom access panel: remove wire nuts, separate the black, white, and ground wires.

Step 3: Remove the old mounting assembly (if needed)

If the new disposal uses the same mounting system and the existing mount is in good condition, you can leave it in place. If you need to replace it:

1. Loosen the three mounting screws.
2. Remove the snap ring (use a flat screwdriver to pry it off).
3. Remove the flange, fiber gasket, and backup ring from above the sink.
4. Clean old plumber's putty from the sink opening.

Step 4: Install the new mounting assembly

1. Roll a rope of plumber's putty and press it around the sink flange.
2. Press the flange into the sink opening from above.
3. From below, slide the fiber gasket, backup ring, and mounting ring over the flange.
4. Secure with the snap ring (it clicks into the groove on the flange).
5. Tighten the three mounting screws evenly until the assembly is snug against the sink.
6. Wipe away excess putty that squeezed out around the flange above the sink.

Step 5: Wire the new disposal

1. Remove the electrical access plate on the bottom of the new unit.
2. Feed the electrical cable through the cable clamp.
3. Connect black to black, white to white with wire nuts. Attach the ground wire to the green screw.
4. Tuck the wires in and replace the access plate.

Step 6: Mount the new disposal

1. If your new disposal has a dishwasher inlet and you have a dishwasher, knock out the plastic plug inside the inlet using a screwdriver and hammer. Remove the plug from inside the disposal.
2. Lift the disposal and align the mounting tabs with the mounting ring.
3. Turn the lower mounting ring clockwise to lock the unit in place.
4. Reconnect the dishwasher drain hose (if applicable).
5. Reconnect the drain pipe to the disposal's discharge tube.

Step 7: Test

1. Turn the circuit breaker back on.
2. Run water into the sink and check all connections for leaks.
3. Turn on the disposal and verify it runs smoothly.
4. Check the dishwasher connection for leaks (run a short dishwasher cycle).

Professional Installation Cost

If you'd rather hire a plumber, expect to pay $250–$500 total for a garbage disposal replacement in Los Angeles — that includes the unit and labor. Most plumbers complete the job in under an hour.

Browse verified plumbers in our directory to compare options, or see our complete plumber cost guide for more pricing details.

Frequently Asked Questions

How long does it take to replace a garbage disposal?

For a DIY replacement using the same mounting system, expect 1–2 hours. If you need to replace the mounting assembly or modify plumbing connections, add another 30–60 minutes. A plumber typically completes it in 30–45 minutes.

Can I install a more powerful disposal than my current one?

Yes, as long as the electrical circuit supports it. Most kitchen disposal circuits are 15 or 20 amps, which is sufficient for any residential garbage disposal up to 1 HP. The mounting system is the same regardless of horsepower.

Do I need a plumber or electrician to replace a garbage disposal?

A plumber can handle the entire job — both the plumbing connections and the electrical wiring. If the disposal is hardwired (no plug), some homeowners prefer to have an electrician handle the wiring portion, but most plumbers are qualified to do basic disposal wiring.

What should I do with the old garbage disposal?

Garbage disposals contain metal and electrical components. Most LA waste haulers accept them as e-waste or bulky items. You can also drop them off at an LA city SAFE center or recycling facility. Don't put them in regular trash.