DIY: How to Replace a Garbage Disposal

The first plumbing job I did in my home when I bought it in 1988 was to replace the old garbage disposal. It didn’t work, and the odor was off the scale.

I purchased a new disposal at the local DIY store, but was unsure of myself. I asked an associate if I could do the job myself- he said, “You sure can.” I got his attention again, and explained I had never done anything like this before. I wanted to know if I could do it. He looked at me, smiled, and asked two questions: Could I handle a wrench, and could I read English? I said yes to both. He explained following the directions was all I needed to do.

That worked well until I got home. Getting the old one off turned out to be the trial of the day. More on that later.

You will need:

• A new garbage disposal unit- read the packages carefully to determine which is best for your needs. I use a 1/3hp unit- not too big.

• Electrical cord for the unit- this is sold separately. I cut the cord off the old one and have used it for subsequent units ever since. It works fine.

• Electrical nuts to cover the ends of the wires

• Any replacement pipes that are needed- take the old ones with you to the store and match them to new ones.

• Screwdriver

• Pliers

• Hacksaw

• Hammer, if needed

• Plumber’s putty

• Silicone caulk

• Plumber’s tape or goop for threaded ends, if needed

Step One:

I love saying this- this is the fun part. Remove the old garbage disposal. Study instructions for the new unit- it will give you some idea of what needs to happen to remove the old one.

Unplug the disposal. I know I don’t need to tell you, but some folks forget.

Cut the cord off with wire cutters and save it if you’re using this cord. If it’s frayed, forget it and buy a new one.

Remove the drainpipes leading to the disposal.

Undo the locking ring and remove the old disposal. Okay, here’s the fun part- mine was so rusted, so locked in I couldn’t even break it loose by tapping with a hammer. And I tapped hard. I finally got a pry bar, shoved it into the rings, and pushed down as hard as I could. While I did this, I noticed the entire sink bowed. The thought ran through my mind that I would wind up replacing the sink any second. When I heard a loud crack, I thought I had indeed broken the sink. I got back under the sink and tapped again with the hammer. The old disposal came off without a hitch. The sink was fine. Go figure.

Of course, I do not recommend doing this. My point is that sometimes the old one won’t come off without a little persuasion. I have no idea how old the old one was, but it weighed nearly 30 pounds. It was filled with gunk. Yuck.

Remove the mounting rings and the drain flange. Clean the opening around the sink drain.

Step Two:

The easy part. Turn the new disposal upside down, and attach the new cord. If the disposal came with its own cord, be happy.

Grab some plumber’s putty and smooth it into a rope. It’s a lot like playing with clay.

Press your rope around the underside of the new flange and place it in the sink drain. When the mounting bracket is tightened, any excess putty will squeeze out.

Under the sink, install the mounting ring and tighten the screws.

Step Three:

Mount the disposal unit into the mounting ring brackets. Make sure the plumbing drain openings are in the same direction of the pipes, or you’ll have to take it off again.

If the sink has a dishwasher, the disposal may have a “knock-out”- that’s a piece of plastic you’ll have to break out first, in order to attach the dishwasher drain. It’s easy- a screwdriver and taps (really, taps) from a hammer will do it. Just remove the plastic pieces before you install the unit.

Cover the threaded ends of pipes with plumber’s tape or goop, and attach the pipes to their proper openings.

Tighten the mounting screws and turn on the faucet. Make sure there are no leaks.

Plug the unit in, run some water in the sink and turn it on. You’re done.

In the twenty years I’ve owned this home, I’ve installed three disposals- I’m not hard on them, I tend to by inexpensive models that don’t last forever. Of course, one bit the dust when a friend’s son decided that toy cars don’t do well in a garbage disposal. He found out it tends to make people angry. His mother paid for the replacement, and I made him help me replace it. He decided he wouldn’t do it again.

Source: Jeff Day (2003). “Home Improvement 1-2-3,” Des Moines, IA, Meredith Publishing Group

Source: The author of this article has over 40 years of experience in diverse forms of DIY, home improvement and repair, crafting, designing, and building furniture, outdoor projects and more.

Reference:

• wwww.homedepot.com
• www.lowes.com