Let’s be honest—dishwasher air gaps aren’t exactly pretty. That weird metal cap next to your faucet? It’s there for a reason, but if you’re redoing your kitchen or simply want a cleaner look, you’re probably wondering: are there any good alternatives?
Short answer: yes. But it depends on your local plumbing codes, your sink setup, and how much risk you’re willing to take on. Let’s walk through what your options actually are—and when it’s okay to skip the air gap altogether.
Wait, what’s the point of an air gap anyway?
Before we ditch it, let’s understand what it does. A dishwasher air gap is designed to prevent dirty sink water from flowing backward into your dishwasher. It creates a physical break (a gap of air) between the dishwasher drain hose and the sink drain system, which stops contaminated water from siphoning back into clean dishes.
Think of it like a backflow preventer for your dishwasher. It’s not about draining—it’s about protecting your water supply from contamination.
Why people want alternatives
Honestly, there are a few valid reasons:
- Looks: That dome on the sink doesn’t match most modern kitchen designs.
- Space: Some sinks don’t have extra holes for mounting an air gap cap.
- Clogs and noise: Air gaps can sometimes leak or make gurgling sounds if blocked.
Best dishwasher air gap alternatives
Let’s talk about what actually works as a substitute—and what you need to know to stay safe and code-compliant.
1. High Loop Drain Method (Most Common Alternative)
This one’s simple: instead of installing an air gap, you route the dishwasher drain hose upward—usually attached to the underside of the countertop—before looping it back down to connect with the sink drain or garbage disposal.
This helps prevent backflow by creating a mini “trap” above the water level in the sink drain.
Pros:
- No visible parts on the sink
- Easy DIY install
- Often allowed in areas without strict air gap codes
Cons:
- Not as secure as a true air gap
- Still allows backflow if the sink drain clogs
- Not code-compliant in some US states (like California or Washington)
Bottom line: If your local code allows it, a properly installed high loop is often enough for residential use.
2. Check Valve (Less Common, More Mechanical)
A check valve is a mechanical fitting placed in the drain line that only allows water to flow one way—out of the dishwasher. It physically prevents reverse flow, like a little one-way door for water.
Pros:
- No visible hardware
- Stops backflow without needing a loop or gap
- Can work in tight installs or under-sink spaces
Cons:
- Not always easy to find or install
- May fail over time or get clogged
- Not always approved as a standalone backflow prevention method
Tip: Some dishwashers already include internal check valves. If yours does, adding a second one might be redundant—or necessary for double protection, depending on your setup.
What doesn’t count as a good alternative
- Just draining into the garbage disposal without a high loop—nope. That’s a recipe for dirty water backing up into your dishwasher.
- Hiding the air gap under the sink—not allowed. The air gap needs to be above the flood line of the sink to actually work.
- Installing nothing at all—unless your dishwasher has built-in backflow prevention and your local code doesn’t require more, this is risky business.
What do plumbing codes say?
This is where things get tricky. Some areas require air gaps by law—usually in newer homes or under stricter municipal codes. California, for example, mandates air gaps for dishwashers, no exceptions. Other areas allow high loops or internal check valves as long as they’re properly installed.
Before you yank out your air gap or tell your plumber to skip it, check with your local building department. Seriously—it’ll save you a headache later if you ever sell the house or fail an inspection.
Final thoughts
Dishwasher air gaps aren’t pretty, but they do serve a purpose. If your local code allows it, the high loop method is a simple and effective alternative. If you’re going for a super clean look, pairing a high loop with a check valve gives you double protection without that metal nub on your sink.
Whatever you do, don’t skip backflow protection entirely. Clean dishes aren’t really clean if they’re rinsed with contaminated water. Gross, right?
Need help planning your install? Check out our dishwasher drain routing guide for step-by-step diagrams and code references.