The garbage disposal has an outlet for your dishwasher to drain into it and the main purpose of the knockout plug in garbage disposal is to create a watertight seal in the event you do not have a dishwasher.
If you connect the dishwasher without removing the knockout plug, the water will back up into the drainpipe and onto your counter. Removing the knockout plug will allow drain water to flow freely through the garbage disposal drainpipe and ultimately out of the trap.
Steps to Remove Garbage Disposal Knockout Plug
- Needle-nose pliers
Step 1 – It is much easier to remove the knockout plug before installing the garbage disposal than it is after. So, if you have your garbage disposal already installed, then we will recommend removing it.
To remove your garbage disposal, unplug it from the circuit-breaker and get underneath it. Now insert the screwdriver or hex key into one of the loops of the mounting ring, turn it to loosen the garbage disposal.
You might need an extra pair of hands to remove the garbage disposal as it is slightly heavy to hold once removed from mounting, otherwise, it could damage the floor or even cause an injury to you.
Step 2 – Before removing the knockout plug, first we have to locate it. The knockout plug is usually located inside the tube near the top of the garbage disposal. If you will insert the screwdriver inside the tube, you will feel something solid is blocking the drain opening. This is your knockout plug.
Step 3 – Now, to remove the knockout plug, insert the screwdriver inside the tube, and tap the back of it with the hammer. Tap it repeatedly until the plug is knocked out.
While tapping the hammer, make sure to place the garbage disposal in such a way that it does not move while tapping, otherwise it could damage the disposal as well the surface.
Once the plug is removed, use needle-nose pliers to reach inside and pull out the plug. Clear all the small pieces of plastic in and around the tube with pliers or with your hand.
Step 4 – As you have removed the knockout plug, now you can mount your garbage disposal and attach the dishwasher line with it. When you will use your garbage disposal for the first time after removing the knockout plug, it will make some noise which is nothing to be worried about.
Now, you can use your garbage disposal and dishwasher together without worrying about anything.