Changing a worn-out garbage disposal can be a 10-minute job–assuming you anticipate everything, use the same brand as the old one, you know what you’re doing, and the person who installed the old one was at least as competent as you.
It didn’t quite work out for me like that the last time.
The failing disposal was an Insinkerator, made by St. Louis’ very own Emerson Electric, though not made in St. Louis. I find Insinkerators are reliable if you take care of them, and they’re the rare appliance made in the USA. You can save some money with a private-label version though, and those are also made in the USA.
Let’s get this out of the way before going any further: Before working on any disposal, turn off the power at the circuit breaker or fuse box. I shouldn’t need to remind you how many ways a garbage disposal could injure you, but absent power, those ways disappear.
Disposals are very simple machines, so there’s really only three things that go wrong with them. Usually they seize up because someone tried to put something down them that they shouldn’t have. When they die of old age, it’s usually because the seals failed, allowing water to get where water shouldn’t get, so the motor shorts out or the disposal leaks, or both.
If you don’t mind messy jobs, you can disassemble a leaky disposal, clean it out, replace the seals, put it back together, and it will probably last another 8-10 years. This one was so bad I regretted trying to salvage the electrical cord.
Of course the other problem I ran into was my predecessor left about three times as much slack was necessary in the wires, then stuffed it down into the disposal, making it really hard to retrieve them.
My predecessor also used some kind of thread lock on the fitting that keeps the cord from getting nicked. Going to the hardware store is a 10-minute job in itself, so that was the end of the 10-minute job. I eventually got the fitting out, but in pieces.
Removing an Insinkerator is rather simple–it twists out with the wrenchette that you use to fix clogs. The instructions describe it well, and it’s really as simple as that–much easier than the Youtube videos make it appear.
If I’d brought an electrical fitting along and opted to cut the cord and live with less slack, I probably would have saved myself an hour.
Slipping the new disposal into place can be tricky but doesn’t have to be. Be sure to line all three tabs up onto the ramps, then you can twist it into place with nothing more than the wrenchette. I opted to use the existing fitting because it was in good shape and the old ones are compatible with the new ones. It’s likely to be harder to slip a big, heavy disposal into place than a 1/3-horse unit.
I reused all of the old plumbing, and there’s rarely any reason not to. Where I tripped up was that my predecessor installed the gasket that goes between the disposal and the discharge on the discharge itself. Maybe that’s the way it was supposed to be on the old model, but when I set the new one up that way, it dripped slowly but consistently. That wasted another 10 minutes, but when I put the gasket in where it belongs, it worked well. Regardless, if you’re reusing old hardware, make sure to use the new seal even if you reuse everything else. The minerals and chemicals in the water cause rubber to break down so you want as much life expectancy as you can get out of that gasket.
The other thing I did while I had the plumbing apart was to check the other joints in the PVC pipe near the disposal. They hadn’t been put together with PFTE tape, so I took those apart and added some tape to get a tighter, better seal on those joints.