sink/disposal backs up into dishwasher/floor

[chang-savoy]

Help. This is the second time in two years that the sink with the garbage disposal has backed up into the dishwasher and then all over the floor.
in-sink-erator disposal and frigidaire dishwasher

[HayZee518]

when the dishwasher drains do you have the garbage disposal running? do you ever fill the sink then drain it? could be because the sink is higher than the dishwasher it is back siphoning into the dishwasher. normally the dishwasher drain has an air gap to prevent a back flow.

[Dan O.]

the second time in two years that the sink with the garbage disposal has backed up into the dishwasher and then all over the floor.

I suggest you look into why your disposal isn't draining properly and also install an air gap (see the link and illustration below) in the drain line between the dishwasher and disposer... if it isn't already mandated by building codes in your area.

LINK > Dishwasher Drain Air Gap



JMO

Dan O.
www.Appliance411.com
The Appliance Information Site
=D~~~~~~

[chang-savoy]

disposal/dishwasher

No, the disposal is not running while the dishwasher is running. I had just emptied the washer and was rinsing dishes to go in. I noticed water running across the floor. I will check what you suggested, any other ideas?

[pushkins]

The dishwasher line into the garbage disposal is higher then the main discharge line from the garbage disposal, it sounds to me like there might be a small blockage in the main line (P trap possibly), try the following test:

Put the plug in he sink and then fill your sink with water, pull the plug out and take notice of how fast the sink empties, it should empty pretty quickly, if it is draining slowly then this would allow the disposal chamber to fill with water and back flow down the dishwasher line.
If this is the case (draining slowly) try removing the P trap and seeing if there are any blockages.

[Dan O.]

Pre-rinsing dishes

I had just emptied the dishwasher and was rinsing dishes to go in.

JFYI. You should not be rinsing (as in under a tap) dishes before washing if that's what you were doing. Only scraping large food scraps from them should be done.

JFYI

Dan O.
www.Appliance411.com
The Appliance Information Site
=D~~~~~~

[ggomeso]

The dishwasher line into the garbage disposal is higher then the main discharge line from the garbage disposal, it sounds to me like there might be a small blockage in the main line (P trap possibly), try the following test:

Put the plug in he sink and then fill your sink with water, pull the plug out and take notice of how fast the sink empties, it should empty pretty quickly, if it is draining slowly then this would allow the disposal chamber to fill with water and back flow down the dishwasher line.
If this is the case (draining slowly) try removing the P trap and seeing if there are any blockages.

what side of the sink do i put the water in?

[HayZee518]

both sides

[pushkins]

As a side note to this, most newer dishwashers are now being supplied with backflow preventer valves.