you said "Straight into " -- does this mean without a high loop ? Do you know what a high loop is? Can you describe how it looks in your case under your kitchen sink counter?

Yes, an air gap would force the crud out onto your countertop where you could diagnose the problem more easily and not contaminate your DW too. If there is that problem.

-david

Chances are, the lack of an air gap isn't your problem. You don't say how old your dishwasher is, what type of detergent you're using, or how thoroughly you scrape dishes before putting them in the dishwasher.

If this is a recent development with a dishwasher that has always functioned properly without an air gap in the past, then chances are, the lack of an air gap has nothing to do with your problem.

If your dishwasher is getting old, then perhaps the drain pump isn't functioning as well as it once did, or you have an obstruction in the drain line. Have you checked to be sure that you don't have anything partially blocking the drain line or some obstruction in the port where the drain line connects to the dishwasher? Either could be the cause of your problem.

There are undoubtably millions of dishwashers out there operating without air gaps while delivering perfectly satisfactory results. The air gap requirement in many municipalities is a fairly recent phenomenon, and does nothing to improve the performance of a dishwasher. If your dishwasher has been doing a good job without an air gap in the past, it should continue to do so.

Food debris left behind on dishes is more likely due to an aging dishwasher with a failing soft food disposer, a drain pump that isn't functioning properly, or a partially clogged drain line. If you're sure the drain line is clear and your dishwasher is an American brand that's more than 8 or 10 years old, it may be time to think about a new machine. Consumers Reports says that a good rule of thumb is that it's generally not worthwhile to repair most major appliances that are over 8 years old.

Should you decide to think about a replacement, you might be interested to note that most European brand dishwasher employ micro-screen filtering systems that prevent food debris from circulating in wash water sprayed thoughout the wash cabinet and being redepositied on the dishes. Most debris captured by the filters is sluiced out of the machine during the drain cycles, but you will need to periodically check and rinse the filter of any large bits of bone or bits and pieces that are too large to be sluiced out.

Most American brand dishwashers, on the other hand, don't employ filters, but rely a grinding mechanism, called a soft food disposer, which pulverizes food debris into tiny bits so that it can be readily sluiced out of the machine in the drain cycles. In this system. pulverized food debris continues to circulate in the wash water, and can be redeposited on your dishes if it isn't completely sluiced out of the machine in the rinse and drain cycles

I don't think an air gap is going to improve your wash results. Barring obstructions in the drain line or drain line port on your disposer, it may be time to think about a replacement dishwasher.

An 'airgap' is not your problem.

An 'airgap' is used as a backflow preventer to disallow waste water from being siphoned back into your potable water supply lines.

Most modern dishwashers have a built-in backflow preventer which eliminates the need for an air gap on discharge lines.

That said, your discharge line from the dishwasher still needs to be secured to the under side of the counter to prevent waste from your waste grinder (garbage disposal) from flowing into your dishwasher.

Ideally, your waste line from the dishwasher should be bored throudh the sink base cabinet at its highest point, and when not, the drain line fastened to the underside of the countertop to prevent garbage waste from entering the dishwasher.