Clogged drain mystery
I cross posted this to the plumbing forum as well:
This morning my kitchen sink clogged up. I removed the disposal and the trap, and snaked the drain with a 25' drain snake. This is several feet beyond what is needed to reach the main drain line in the basement, and the resistance I meet with the snake as it goes through bends in the line confirm that I have reached the main drain line. However, it still won't drain. What's strange is that the upstairs bathroom drain, which ties in upstream of the kitchen line, has no problem. Here's a schematic to clarify:
To summarize, the upstairs bathroom drains just fine, the kitchen drain is clogged, and I've snaked the kitchen drain to the main drain pipe. I don't understand how this can be, what am I missing?