Find out how to choose and install a garbage disposer to cut down on food waste at home. Get tips on considering four basic questions when you make your choice and learn the best way to use and care for your new disposer.
LESLIE: Well, an easy way to cut down on food waste at home is to install a garbage disposer. You can send leftover fruit and potato peels, veggie stubs and all kinds of other waste right down your drain.
TOM: And this is one of those appliances that once you own it, you never want to be without one again. To help us understand the options and what it takes to install a garbage disposer, we welcome Richard Trethewey , the plumbing and heating contractor from TV’s This Old House .
RICHARD: Hi, guys. Nice to be in The Money Pit.
TOM: It’s a pleasure to have you.
Now, manufacturers call these “food-waste disposers.” What should homeowners be asking themselves when shopping for one?
RICHARD: Well, there’s four basic questions, I think. One is what type of garbage disposer  do you want to get, what size, any special features you want to get and do you have a septic tank or a septic field?
TOM: So let’s start with type. How many types are there?
RICHARD: There are two. One is called “batch feed” and the other is called “continuous feed.” Batch feed, as its name suggests, you put food down into the disposer and then you put a stopper, that is also the active switch for the disposer, down into the drain. You turn it and there’s a little magnet there that brings that disposer on. The batch feed is perceived to be much safer because there’s no chance of spoons or unwanted things going down the drain and no chance of hands going down there.
RICHARD: The other is continuous and that is there’s a switch somewhere, either under the sink or on the wall. You turn it on and most pro chefs would want to have that because you can move food down while you’re doing food prep and it’s …
LESLIE: Mm-hmm. And that’s really like a volume thing.
RICHARD: That’s right. That would be for the bigger use, yeah.
LESLIE: Now, what about noise? I mean I don’t have one. I imagine that they’re quite a noisy appliance to have in your home.
RICHARD: Well, there are choices in terms of the size and with that comes the amount of insulation. The basic builder model, the one that we call the “builder model,” is the cheapest thing. It has almost no insulation. It sounds like a freight train underneath the sink. It usually makes the sink jump up and down.
And then as you go higher, you get more horsepower and you also get more insulation to really make it quiet.
TOM: Now, what about a septic system? If you have a septic system, can you actually have a disposer?
RICHARD: There are some disposers that are made specifically for septic systems, if you have a disposer – a modern disposer – that can really grind that food to a fine puree, really, to get it into the septic field. But many of these disposers also have a feature that can add a little container on the side of the disposer that adds an enzyme to help break down those foodstuffs when they go down to the septic system. So the answer is yes.
TOM: That’s good advice.
Now, what about installation? Is it difficult to install a disposer? Are there any common pitfalls that people – mistakes that people make?
RICHARD: Well, an installation of a disposer is two-part. One is you have to install the flange up onto a sink. And that’s the big 4-inch hole that you can see from the sink side. And then you have to attach the disposer to that flange and that can become tricky to try and hold that disposer up and then lock this ring in to hold it in.
RICHARD: So sometimes you have to put a cardboard box under it or some sort of lever, because it …
TOM: Because it’s pretty heavy.
RICHARD: Really, the high-quality ones are heavy, so you’ve really got to muscle it up there.
LESLIE: Now, Richard, I imagine these things jam quite often. What can you do in the event of something getting stuck in your disposer?
RICHARD: Well, you certainly hope they don’t get jammed often.
LESLIE: Well, if you’re cramming everything you’ve got down the sink …
RICHARD: And actually, I’ve got to tell you, the highest-end disposers actually have a feature where each time it comes on or if it did jam, the motor would automatically reverse and go the other way.
TOM: Oh, interesting.
RICHARD: So it’s an anti-jamming feature. In some of the basic ones, though, they are going to jam and so in that case, there’s a couple things to look for. Underneath every disposer is a little red button. It’s a little reset button. It’s much like a circuit breaker on your electrical panel. And so if it overheated because it was jammed, that button would pop out. You have to get underneath there and just reset that button.
Now, that may not be enough. Because if the grinding wheel – that thing that is going to grind up the food that’s inside the disposer – is jammed, then you may have to mechanically clear that jam. And so, many of these disposers come with a little Allen-style wrench; it’s a little offset wrench. Usually comes in a package that hangs near the disposer, we hope. And from directly underneath the disposer, underneath the kitchen sink, you put it into that center spot; there’s a little opening there. And you can just clear back and forth, back and forth to try and clear that chicken bone or whatever’s in there.
TOM: Now, what’s the best way to care for your new garbage disposer? Any special maintenance associated with them?
RICHARD: Never put any drain chemicals down there. It’ll eat up the seals.
TOM: Yeah, good point.
RICHARD: Don’t do that. I think – I will tell you that a lot of people put a little lemon down there or something to keep it fresh down in there. There’s not a lot of maintenance you have to do but you do have to be sure you run water whenever you’re running the disposer.
TOM: Because otherwise, you’re not going to move the food. You need some water …
RICHARD: That’s right. And it wants to keep it cool and lubricated, as well.
TOM: Yeah, good point. Richard Trethewey, the plumbing and heating contractor from TV’s This Old House, thanks so much for stopping by The Money Pit.
RICHARD: Great to be here.
LESLIE: Alright. You can catch the current season of This Old House and Ask This Old House on PBS. For your local listings and step-by-step videos on many projects and some information on how you can choose a garbage disposer, visit ThisOldHouse.com.
TOM: And This Old House and Ask This Old House are brought to you by GMC. GMC, we are professional grade.