This one needs a licensed pro
Likely cause: a leak in the pipes or fittings below
Water is escaping from a pipe joint or fitting under the sink, not past the stopper. Find the first drip, then call a plumber.
Why this happens
InSinkErator's page on leaking garbage disposals lists adjacent plumbing as one place a leak near a disposal can start, and says to tighten joints as needed or find a certified plumber. It also says that if you cannot find a leak, the water may come from other sources: water filters, the dish sprayer, the faucet, the dishwasher drain hose, the sink or countertop seam, or countertop joints. Family Handyman says to test the strainer first to be sure the leak is not from a pipe joint.
What to do right now
- If water is spraying or gushing, or a supply line or shutoff keeps dripping and will not stop, shut off the main water supply without forcing any shutoff that will not turn. Kohler's strainer installation guide also begins by shutting off the main water supply. Keep clear of any plug, cord or outlet under the sink and call a plumber right away.
- If there is a garbage disposal or any plugged-in device under this sink, turn off its breaker before you dry anything or add water. Bob Vila says to unplug a disposal and turn off its power at the breaker box before checking it for leaks. If a plug, cord or outlet is wet or sitting in water, do not touch it, do not add water, and call an electrician as well as a plumber. Turn off its breaker only if you can reach the panel safely.
- Keep the faucet off. If the drip is on a water supply line or a shutoff, shut off the water supply and do not force a shutoff that will not turn. If it will not turn, shut off the main water supply instead, without forcing that one either, and call a plumber.
- Empty the cabinet. Spread a sheet of newspaper flat over the cabinet floor and tape it down, as InSinkErator describes. Water that drips will leave a wet spot.
- Put stoppers in the sink, fill it, and leave it full for a while. Look for leaks. Then remove the stoppers, let the sink drain and look again. InSinkErator then runs the water and the disposal for a last look. If there is a disposal in this sink, keep its breaker off and stop after the drain test.
- If you cannot tell where the water comes from and this bowl has no disposal, close the stopper, fill the bowl a few inches and touch a facial tissue between the bottom of the strainer and the sink, as Family Handyman shows. If the tissue picks up water, the strainer is leaking, so go back and choose the answer about the strainer.
- If you find no leak, InSinkErator says to keep the paper in place for a few days. If you still see nothing, check the water filters, the dish sprayer, the faucet, the dishwasher drain hose, the sink and countertop seam, and the countertop joints.
- If a chemical drain cleaner has gone down this sink, do not take any pipe apart. Family Handyman says caustic chemicals that did not clear the clog are a danger to anyone who takes the trap apart. Call a plumber and say what you used.
- InSinkErator says a loose joint can be tightened. If a joint keeps dripping after it is snug, or a pipe or fitting is cracked or corroded, stop and call a plumber.
When to stop. If a supply line or shutoff drips and the water will not stop, shut off the main water supply, without forcing a shutoff that will not turn, and call a plumber. If no shutoff will turn, leave the area dry and clear of electrical devices and call a plumber right away. If water is spraying or gushing, call a plumber right away. If a joint keeps dripping after it is snug, stop and call a plumber.
What to tell the plumber
- Where the first drip forms: the trap, a pipe joint, a hose or a water line.
- Whether the newspaper showed wet spots, and where.
- Whether the leak shows with the sink full and plugged or while it drains.
- Whether a disposal or dishwasher connects to this drain.
- Whether a chemical drain cleaner has gone down this sink.
Build the full list: what to tell the plumber.
Start this troubleshooter over
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