I have a problem with waste water flooding up through the sink erator and all over the kitchen counter, each time the dishwasher is used. I have taken to placing a rag about the erator and capping the whole thing with an upside down glass measuring cup to direct the water to flow only into the sink. Is this a simple fix or should I consult a plumber??
There is a clog somewhere. Sounds like your dishwasher drain line goes into your disposal which sometimes causes issues. It sounds like the water is coming out of the air gap on top of your sink. If the water is also coming up through the disposal the blockage is in your drain somewhere after the disposal in the P trap or waste line. If the water is only coming out of the aerator up on the back of the sink you probably have a block in the DW drain line between the aerator and the disposal. This could be a kink in the line or a debris blockage. If so, this is not a hard fix. Check for kinks first. Something may have been shoved up against the line under the sink and kinked it. If you don't see a kink you need to disconnect the line from the side of the disposal and clean any debris you might find out of the line.The debris could be anywhere between the aerator and the disposal. If it's up near the aerator it may be a difficult to reach but I'm pretty sure that will solve your problem.