double sided kitchen sink, with disposal, stopped draining. We tried a plunger, but during the process we noticed our floor was flooded with water coming from the dishwasher which is in the island. Used 25ft snake, found nothing. Over the last few days we have 3X used very high powered drain opening products, no success! When we run water into the sink (either side) it drains into the dishwasher. The dishwaher is not connected to the sink or disposal. There is an air gap on the water drain pipe of the diswasher, which may have been installed when we put in the island 20+ yrs ago. Please help.
I never recommend using chemical drain products; they can damage your drain pipes permanently; better to snake, or as someone above has mentioned, a wet/dry vac. Running your taps and observing how much time it takes for the drains to back up to the kitchen area can sometimes offer a clue as to how close of far the blockage is located. Do this after an hour or longer has passed, giving any trapped water time to drain off slowly through any blockage. First thing in the morning, usually.