A garbage disposal spraying water is not what you'd like to find under your kitchen counter, especially when the appliance has been leaking undetected for a while. Other than the inconvenience of having to remove and clean everything you've stored in the cabinet underneath the sink, there's also the possibility that water from the leaky disposal has damaged your floor or subfloor.
Garbage Disposal Leaks When Running
If you notice that the garbage disposal leaks when running but doesn't leak when it's not in operation, you'll know that the problem lies within the garbage disposal and not with the plumbing in your home.
Even if you can't see that your garbage disposal leaks when running because you don't often open the cabinet underneath the sink, your other senses can alert you to this problem. You may hear a dripping noise underneath the sink when your disposal is running or shortly after you turn off the disposal. You may see water running onto your floor from underneath the cabinet, and you may also smell a foul odor from food waste that you've run through the disposal.
Pinpointing the Location of the Leak
A garbage disposal leak typically comes from one of three places: the top of the disposal, where it's joined to the sink drain; the sides of the disposal, where the hose or drainpipe connects to the disposal; or the bottom of the disposal. But since gravity pulls water downward, it may be hard to tell exactly where the leak is.
First, remove everything in the cabinet underneath the sink and place a bowl or bucket under the sink if the garbage disposal splashes water or leaks during your diagnostic test. Put the sink stopper in place to prevent water from draining and flowing to the disposal and fill the sink with several inches of water. As you remove the stopper, look underneath the sink to see if you find any leaks. If you see water leaking from the water supply lines or the pipes that take water away from the sink, the problem is not with the disposal.
Fill the sink again, but this time start the disposal when you remove the stopper. Now check to see where the garbage disposal splashes water and if the disposal is leaking from the top, sides or bottom.
Fixing the Leak
If your garbage disposal is leaking from the top, Mr. Rooter Plumbing notes that it probably means the putty around the seal has deteriorated or the sink flange needs to be replaced. If you decide to replace the flange yourself, be sure to interrupt the power to your disposal before beginning work.
If your garbage disposal is leaking from the bottom, the seal that's inside the appliance may be worn out. You may want to have a licensed plumber confirm this, because repairing the seal may not be worth the cost compared to replacing the entire disposal.
If your garbage disposal is leaking from the sides, it could be coming from the point where one or both of the two drain lines connect to the disposal. The metal clamp that secures the lines to the disposal may simply be loose. All you have to do to remedy this is use a screwdriver to tighten the clamps. It's also possible that there's a crack in the housing of your garbage disposal — the outer shell — and if this is the case, you'll have to replace the disposal.
Victoria Lee Blackstone is a horticulturist and a professional writer who has authored research-based scientific/technical papers, horticultural articles, and magazine and newspaper columns. Her writing expertise covers diverse industries, including horticulture, home maintenance and DIY projects, banking, finance, law and tax. Blackstone has written more than 2,000 published works for newspapers, magazines, online publications and individual clients.