Buying a New Garbage Disposal

We have all have been in that situation. Your dinner guests are over, you’re cleaning up, you’ve just crammed an entire three course meal down your garbage disposal, hit the switch, and nothing happened.  The last thing you want your guests to see is you underneath the sink performing emergency plumbing in your best clothes.

The next day, you decide you are not going to make this mistake again. You’re going to buy the best garbage disposal there is. You head down to the local hardware store, hit the right aisle, and that’s when you realize you have no idea what you’re looking for.

What the heck is a badger? How about a bone crusher? That sounds good. How much horsepower do I need? These are just a few of the questions I get every time I find myself in the disposal aisle in my plumbing uniform.

The first thing I tell people is: “Are you sure you need a new disposal?”  Nothing is more embarrassing to a home owner than to have me show up at their house to fix their disposal, only to find the little reset button is sticking out. This is a small button on the bottom of most disposals that simply resets the motor in the case of overloading. Sometimes it’s just that simple. You shut the disposal off, reset the button, and try the disposal again. If this does not work, all hope is not lost. Also, on the bottom there is usually a small octagon hole for a special wrench to unjam your disposal. Try inserting the tool or the correct Allen wrench in and giving it a spin to free it up.

So, let’s say you have already tried all of that and you’re done. You want the new disposal and that’s that.  So which one do you choose?

The first thing to look at is what kind of connection to the sink do you have. About 70% of disposals have what we call an ISE metal flange. You will find this style on every InSinkErator model. (ISE being an abbreviation.) If this is the case, try to find one with the same flange. This will keep you from having to change out your flange, which is the trickiest part. If you don’t have this type of flange, then it won’t matter, and you need to change out the whole thing, especially if it’s plastic.

The next thing you will be looking at is the horsepower. You can buy anything from 1/3 horsepower to 1 full horsepower. One thing to keep in mind is that in all my years of plumbing, I have never seen a disposal fail because there wasn’t enough horsepower. I have often wondered; do you really want your disposal to be able to grind up a whole rack of lamb and send it down your pipes? That being said, you do get what you pay for. A 1/3 HP ISE disposal, for the most part, will get the job done. It probably won’t last that long. Maybe 4 to 5 years. Not because of the lack of horse power, but from the case being galvanized instead of stainless steel. The case starts to rust away after a few years. This doesn’t make them bad, just not long lasting. A half HP disposal is most common. You can get these with stainless or galvanized grinding components. Beyond this, you’re really just looking at how quiet you want the disposal. A 3/4 HP disposal is twice the size of a 1/2 HP but the case is the same. You’re just seeing all the extra insulation to make the disposal quieter.

As for brands, InSinkErator and KitchenAid have been around the longest. If you’re on a septic tank InSinkErator has one that adds enzymes to each spin of the disposal, helping your septic tank keep a balance. Watch out for companies that only have one model, or stores that you wouldn’t normally be buying a disposal at in the first place. Plastic flanges are always a bad idea. No, they won’t rust. But it just can’t hold up against the constant vibration.

Another question I’m asked is: “How can my disposal be clogged? I bought a really expensive one!” Keep in mind, it’s usually not so much that the disposal didn’t do its job. It’s what you put in them. Pasta is usually never a good idea. But if you do put pasta down the disposal, slow is the key. Water is a good equation. The food itself is not going anywhere without some water to push it down and carry it away. Last but not least, they are food waste disposals, not garbage disposals. No drain line was ever meant for bottle caps and glass.

There is one more common question I’m frequently asked: “Can I have a garbage disposal on a septic tank?” There is an old saying that you can’t. Most people believe this is because that it will mess up the balance of good bacteria that makes a tank work.  This is false. With everything that goes into a septic tank, ground up food is the least of your worries.

I believe where this theory originated is that homes that are on septic in some areas are the older homes. If your home is built in the 60’s or earlier, it’s a good chance that your kitchen drain line is an old galvanized pipe. If this is the case, having a disposal on it will most likely give you problems. Whereas a home built in the 80’s through today will have plastic pipes, making for a smooth surface to slide on.

As you’re leaving with your new disposal, don’t forget to check and see if it has a built-in cord. Most do not, which is surprising, since they won’t work without one. Happy hunting. And get help if you need it.