Mind the Air Gap
If you have a dishwasher in your house you most likely have a cylindrical fixture like this sticking up an inch or two from your sink counter. 
It's not a second faucet the builder forgot to install. It's called an air gap.
The purpose of the air gap is to prevent backflow into the dishwasher. The dishwasher's drain pipe connects into the garbage disposal or the drain below the sink. If there were a backup in the disposal or sink, dirty water (sewage) could flow backwards into the dishwasher though its drainpipe and contaminate clean dishes inside. The air gap stops that.
The air gap also acts as a relief valve, of sorts. If the disposal or sink are blocked up, water from the dishwasher would be unable to drain, and would fill up inside the washer until it started leaking out the door. Or would surprise you with a nasty splash! when you open the door. The air gap provides an alternate means for water to drain out of the washer, by coming out the vents in the air gap and spilling across the top of the sink.
This is exactly what we caught happening last weekend: water was pouring through the vents in our air gap, across the sink counter, and into the sink.
Time to grab the toolbox and a bunch of spare towels and get busy.
See what we find in Part 2....
It's not a second faucet the builder forgot to install. It's called an air gap.
The purpose of the air gap is to prevent backflow into the dishwasher. The dishwasher's drain pipe connects into the garbage disposal or the drain below the sink. If there were a backup in the disposal or sink, dirty water (sewage) could flow backwards into the dishwasher though its drainpipe and contaminate clean dishes inside. The air gap stops that.
The air gap also acts as a relief valve, of sorts. If the disposal or sink are blocked up, water from the dishwasher would be unable to drain, and would fill up inside the washer until it started leaking out the door. Or would surprise you with a nasty splash! when you open the door. The air gap provides an alternate means for water to drain out of the washer, by coming out the vents in the air gap and spilling across the top of the sink.
This is exactly what we caught happening last weekend: water was pouring through the vents in our air gap, across the sink counter, and into the sink.
Time to grab the toolbox and a bunch of spare towels and get busy.
See what we find in Part 2....