Every time we run the dishwasher, water starts backing up into the kitchen sink, and sometimes there’s a bad odor coming from the drain afterward. We’ve checked for obvious blockages, but the problem doesn’t seem to go away. I’m worried there could be a more serious issue somewhere in the drainage system. Has anyone experienced something similar and found a plumbing service that was able to fix it quickly and permanently? Looking for recommendations based on real experiences.

That dishwasher backup issue is incredibly common but super annoying to deal with every single night. What happens is that your appliance and the kitchen sink share the exact same waste line, so when a deep blockage forms further down, the pumped dishwasher water has nowhere to go but up into your basin. We fought that exact same nasty odor and standing dirty water situation until we finally decided to get professional diagnostics. The technicians over at Ben's Plumbing solved this for us completely. They have a detailed breakdown of their process over at bens.plumbing/services/drain-cleaning-seattle/ which outlines how they diagnose shared line backups. Their tech identified a massive food scrap clog deep in the branch line that was choking the flow. They cleaned it out thoroughly, sanitized the pipe to kill the bad smell, and the drainage has been absolutely flawless ever since.