I have small main house and smaller unattached house-like mother-in-law dwelling. Both houses have shower, toilet, sink. Yesterday in main house I noticed clear water bubbles in the sink and simultaneously in toilet that went on for maybe a minute or less. Odd, I thought. Then in other house, later that day, I discovered the drain/sewer had evidently backed up in an explosive way in shower and toilet. A mess. Can anyone tell me what's going on and what I should do? Should I expect more and worse to happen? I'm certain that the two occurrences (clear water bubbles in main house and dirty, explosive mess in smaller, detached house) must be connected. Never happened before in 10+ years we've lived here (Seattle). Really appreciate any help!!! Thanks.
It is very common to see (and/or hear) all manner of bubbling and gurgling when you have a partial or complete main line sewer clog. Call a reputable drain cleaning service. You can safely assume that running a cable down the line from the smaller house will get to the clog, but let the plumber tell you that because they often "guarantee" to clear the clog. Make it a point to be home when they do it, so you can inspect any material they drag up out of there. They may also be able to let you see what is going on using a borescope camera.