garbage-disposalplumbing
I'm planning on buying a garbage disposal for a sink that does not currently have one. All of the installation instructions I have found assume that I would be replacing a garbage disposal rather than installing one in a sink that only has a drain.
Will installing in a sink without an old garbage disposal require any additional skills, equipment, or parts beyond an ordinary replacement? What installation steps, if any, will be different?
A GFCI is a good idea because of the location of the outlet. However, I don't think that a GFCI that can simultaneously protect two circuits even exists (and I doubt one would fit into a single-gang box if it did exist), so I believe you have a couple of options:
Install GFCI breakers on the dishwasher and disposal circuits, and use a regular outlet under your sink with the tab between the screw terminals broken off. This may be what you already have; the breakers will have a Test button on them if so. If the supply for the disposal runs to the switch first then to the outlet, this is the only way that the switch will be covered by the GFCI. In your place, this is what I would do: safer and less work, albeit a little more expensive.
Use GFCI outlets. As I said above, you'd need two GFCIs to protect your two circuits, so you would have to install a double-gang box in place of the existing gang-box or add another single gang box then run the wiring for one of the appliances to it instead (in your place, I'd do the latter and use a remodeling box for the new outlet). However, this means that the switch for the disposal wouldn't be covered by the GFCI, potentially risking an electric shock.
Have a look at the trap under your sink. Assuming it's PVC with large plastic nuts, all you should need is ChannelLock pliers:
Unscrew the trap from the wall and disposal, and clean the trap itself, or snake the drain going into the wall, depending on where your clog is. Be sure to have a bucket and towels handy since there will be water backed up before the clog and in the trap.
If you can't find the clog either in the trap or with the snake, and you know it's further down the drain (try running some water through the disposal and into the bucket with the trap out), then I have family that swear by these drain bladders that attach to a garden hose, get inserted into the drain (past the vent) and they swell up to seal your end of the pipe while sending water down until the clog is forced out:
Each one of these will cost around $20 give or take, well less than a visit from a plumber.
Best Answer
Most installation kits will come with the replacement sink basket that the disposer will mount to. You'll need plumber's putty to seal the basket as you install it. Typically it is just a nut or snap ring.
Some of the drain pipes will need to be rearranged to connect to the offset outlet on the disposer. This is basic plumbing, and with patience an a few trips to a hardware store can generally be done. Do not permanently remove the waste trap. The work can difficult without experience, consult a good book on plumbing or hire a licensed plumber. You will also need electrical power and a switch for the unit, which may require a licensed electrician.
Also sewer districts have been making rulings about the use of disposers in their jurisdictions. Some encourage their use, most are starting to discourage or ban units.