Garbage Disposal Question

[atcctl]

When I run the garbage disposal the water comes up in the sink next to it. Otherwise both sinks drain fine. Why does the wtaer come up in the other sink when the disposal is run?

[Steve]

atcctl wrote on 13 Feb 2008 in group alt.home.repair:

Most likely it's because the plumber used a straight connection instead of a baffeled connection, which is designed to stop this problem. You might also have a partial blockage in the drain line.

[SJF]

[S. Barker]

Because your two drains "tee" into each other right under the sink and go into a single trap. Proper kitchen sink plumbing has two traps, each dumping into a vertical pipe of the next larger size.

s

[Red Green]

atcctl wrote in news: [e-mail]:

As said, could be a blockage. Pic is worth 1k words. Take a pic or two of piping under your sink and post to

Might help.

[atcctl]

Pictures for the sink as requested:

[Edwin Pawlowski]

I can see a potential problem. I have a double sink and use one trap. The trap, however, is lower than what your is coming from the disposal. You can pump water literally right across the tee and up the other drain line. Mine on the right goes straight down to the trap, the one on the left comes out of the disposal and goes straight down, then over to the trap.

In spite of what one poser said about the need for two traps, my single trap has worked perfectly for the past 27 years.

[Bob]

The problem is that the disposer thrusts out waste material with sufficient force that it doesn't fall down the "T" immediately -- instead it gets thrown into the other sink. A better solution would be to use an "L" from the disposer output to send the stuff straight down to the trap. In the vertical run to the trap you may be able to use a "T" for the second sink drain. The combination of gravity and no bend from the disposer reduces the likelihood of waste backing up into the other sink. However, it appears that the drain line to the wall is too high to accommodate the "T," so double traps may be the only solution. Just have the disposer output take a straight shot to the wall.

[hallerb]

the real solution is two traps with two drain lines combining several feet below sink level.

had this problem with my old house, in prep for sale it was a must fix item.

plumber did this one, and when we re do the kitchen here i will do this too