The best part about this common issue is that in most instances anyone can fix the problem regardless of their skill-set. Additionally, you won't necessarily have to purchase any tools in order to get your disposal back in working mode. Most disposals come with an Allen wrench attached to them which should be the only tool you may need to fix a humming garbage disposal.
The horror movie image of victims having hands and arms severed in a garbage disposal is entirely a Hollywood invention. In reality, the blades inside a garbage disposal are rather dull grinders, not gleaming, razor-sharp sabers. That is not to say that a disposal should be taken lightly—it is indeed possible to be painfully injured if you don't practice basic safety measures. 
Throw some ice down once in a while. While ice will not sharpen the shredders (as is commonly believed) it does knock off any debris buildup on the sharp edges that keeps them from grinding food properly. For better results, make special ice cubes from pure lemon juice or vinegar, or alternate with biodegradable cleanser (label them in your freezer!) Cover and seal ice trays used in your freezer for cleanser, and do not reuse trays for food or drink after having been used for cleanser. While using the disposal, be sure to run cold water at the same time.

We’re starting with clogs because they’re actually only *kind of* garbage disposal problems. Technically, garbage disposals can get jammed (see below!), but if water stands in your sink and takes forever to drain, it’s probably because the kitchen sink pipe has been clogged. Many different materials can cause clogs, from sediment, to scale, to grease, to food remains. Depending on the culprit, clogs may begin to smell. Ideally, your garbage disposal should have ground up debris enough that it wouldn’t clog anything up, but nobody’s perfect.
There are two main types of garbage disposers—continuous feed and batch feed. Continuous feed models are used by feeding in waste after being started and are more common. Batch feed units are used by placing waste inside the unit before being started. These types of units are started by placing a specially designed cover over the opening. Some covers manipulate a mechanical switch while others allow magnets in the cover to align with magnets in the unit. Small slits in the cover allow water to flow through. Batch feed models are considered safer, since the top of the disposal is covered during operation, preventing foreign objects from falling in.
Why am I writing a review about my beloved garbage disposal? Why am I referring to it as my "beloved" garbage disposal? I replaced a different garbage disposal from Costco; it had lasted a few years before giving up the ghost (the metal teeth within had basically corroded and broken off). Even before it met its untimely end, it had been loud and took a long time to grind things up--despite it being 1-1/4 horsepower!
STEP 4 – If you must use your hands (again, not advised) to pull out all that funky goo, see STEP 2. The disposal must be powered off and unplugged. No exceptions. Not even on a double-dog dare. Also, make sure your hand will actually fit into the opening so that you can eventually remove your hand from the opening. You may need your hand later. If you think it is going to be a tight fit, I’d suggest that you not try it all. You’ve been warned.

I was disappointed with the pressure of a tub and shower that were plumbed with 1/2 supply lines (2nd floor). Could be low pressure from the street, but I want to replace with 5/8. Plus, I'd like to have 2 back to back showers, one inside and one outside. So, I had intended to bring a 1 supply to both, then branch up to valves and shower head with 5/8. Finally, I thought pressure from the street was typically 55 to 70 psi and I am concerned if pvc can take that.Any thoughts?
If water is leaking from the disposal it more than likely needs a seal replaced but also could be a more serious problem. A leak can occur at the rings that are installed around the sink’s drain hole, called the sink flange. In that case, it can either be that the rings need to be tightened or that the plumber’s putty is faulty and needs to be reapplied correctly.
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Abt carries both types of garbage disposal systems, continuous and batch feed. Continuous feed disposers are turned on and off with a power switch. They usually have a shield surrounding the hole in the sink so things do not come back out while being ground for disposal. Some continuous feed disposals have a reverse setting to help reduce jamming. Batch feed disposals operate when a lid is engaged, making them safer. They are a good option for families with children because food is unable to fly out of the sink. Batch feed food waste disposals are usually more expensive than the continuous feed disposals.

Garbage Disposal Installation