Dishwasher Drain Hose Too Long? Here’s What to Do

Dishwashers are a huge timesaver. Instead of having to spend what can feel like hours washing dishes by hand, you can simply plop them in the dishwasher and have them washed quickly. This means you don’t have to wash them yourself and can instead do other things. But when the drain hose is hanging down in the bottom area of the sink, the hose and the washer itself can become annoying. What do you do when the dishwasher drain hose is too long?

Dishwasher Drain Hose Too Long?

There are two ways to fix a drain hose that is too long. An air gap can be installed, or the high loop method can be implemented.

Although these two ways to fix a dishwasher drain hose that is too long are very different, they will both fix the problem. Both will make it so that the hose isn’t as long and doesn’t hang down taking up space beneath the sink. They also both fit regulations in place for when dishwashers are in houses that prevent wastewater from going into the dishwasher. Wastewater in the dishwasher would smell and make a giant mess. To learn more about the two options to prevent this, keep reading!


Why Is It Too Long?

There are a few reasons that the drain hose could be too long. It could be that the hose itself is really just that long. All houses are built differently, and all kitchens have different layouts. By sending new dishwashers with very long drain hoses out, manufacturers are trying to ensure that the hose will be able to get installed no matter where it is placed. This is actually a good thing because then you will not have to go out and purchase a new one if the hose is too short.

The other possible reason for the drain hose being too long is that it was installed incorrectly. Sometimes the hose can be installed in the wrong place, meaning that it could be connected to the sewer line instead of the P-trap, which is something that helps prevent gases from coming back into your home. The sewage line is lower down than the P-tap, so this could be the reason for it appearing to be too long.

For a visual of this, and more information on why the dishwasher drain hose is supposed to be connected to the P-tap, check out this website. Also, the drain hoses are supposed to be either installed with an air gap or with the high loop method right away. This is a regulation for everywhere, not just certain states.


Why Can’t it Be Long?

Other than the fact that a long drain hose takes up space underneath the sink that could be used a variety of other ways, having an air gap or high loop also prevents backflow. If you don’t know what backflow is, it is when the water flows backward. This would mean that contaminated water could end up in the dishwasher washing the dishes instead of clean water. And yes, by contaminated I mean wastewater from the sewer.

Obviously, this is something that we want to avoid happening because it will be a giant mess that you would have to clean, be very smelly, and turn into a big stressful situation in general. The only way to avoid all this is by getting the drain hose set up the way it should be. That is where an air gap and a high loop come in. Both are ways to prevent backflow from happening, meaning that you will not have to deal with the giant, messy situation that backflow can cause.

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Air Gap

I’m not going to lie, air gaps are kind of ugly and once installed, seem like a pretty useless thing to have even though it does serve a purpose. They sit about two inches above the sink, so it will be, most likely, a piece of metal just sitting there. However, it completely separates the hose that has wastewater from the dishwasher drain hose, meaning that it is impossible for dirty water to go into the dishwasher. But how does it really work?

How it works

An air gap makes it so that two different hoses do not connect in any way. This means that the hose that has wastewater is not connected to the dishwasher drain hose in any way, making it impossible for wastewater to enter the dishwasher. Part of the air gap connects to the dishwasher drain hose while the other part connects to the wastewater hose. At the highest point of the hose, the water will leave the tube and be in the air gap.

From the air gap, it will then go into the wastewater hose where it will then end up at a drainage location. The air gap itself will be installed above the countertop, it will just be a small piece of metal, most likely, while both of the hoses will be underneath the sink. But, they will both be much shorter than the dishwasher drain hose was before having the air gap installed. And you won’t have to worry about wastewater entering the dishwasher. It will most likely be metal, not plastic because metal will hold up better and last for a much longer time than plastic.

Is it needed?

An air gap is the only way to ensure that wastewater does not enter the dishwasher. That being said, it is not necessarily needed. There is another method of preventing backflow, which is the high loop method. Having one or the other of these two methods is required, but the air gap specifically is not required in most cases.

In places where food and drinks are made, an air gap is required. So all restaurants are supposed to have this. But residentially, it is only required in a few states. Before making your choice between the air gap or the high loop, make sure that your state is not one of the few that requires an air gap in residential areas.


Luckily, installing an air gap is a fairly easy process. So easy in fact, that you probably won’t even need to call a plumber in to do it for you. First, look underneath the sink for the air gap hole. Most counters come with this hole pre-made. It may be covered, and if this is the case just pull the cover off. If there is no hole, then a hole will have to be made.

You can still choose to do the project yourself or call in a professional to do it for you. Once you have found or made the hole, connect the drain hose to the smaller side of the air gap. You will then connect the wastewater line to the other part of the air gap. Then, push the air gap through the hole in the counter, making sure it is secure, removing the vanity before this, and replacing it once everything is secure. All that is left is to test the dishwasher to be sure everything works perfectly. For more details about the installation process, check out this website.

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Dishwasher drain hose installer

High Loop

Another way to prevent backflow is by using the high loop method. Although a few states require the air gap, and the air gap is required in all places where food and drinks are made, this is a good option for those that live in a state that does not require an air gap in residential areas. It is much easier to do yourself and does not take that much time at all. And once done, you hopefully won’t have to deal with the possibility of backflow ever again. Also, the reason for doing a high loop is very similar to the reason for doing an air gap. A high loop is just easier.

How it works

The basic reason for doing a high loop is the same as an air gap, getting the drain hose up high. The air gap goes above the sink, but the high loop is all underneath the sink. Basically, you are securing the drain hose to the highest point underneath the sink. The drain hose runs from the dishwasher to underneath the sink, where it will be secured in some way to the highest point underneath the sink. It could be secured in a variety of ways, it doesn’t really matter as long as it is secured.

It will then connect to the P-tap, not directly to the waste line. The wastewater is not likely to backflow when the hose is this high, though it is not impossible. So the high loop may not be a full-proof method to prevent backflow, but it will definitely make it harder for backflow to happen and clear up a lot of space underneath the sink.

Is there one already?

When first getting the dishwasher installed, you may notice that the drain hose is connected to the dishwasher in what appears to be a high loop already. Do you still need a high loop underneath the kitchen sink? Despite the fact that there may already be a high loop connected to the dishwasher itself, you do still need one underneath your sink as well. For the house to be up to code, it is required that the high loop is in place. The only reason you would not need the high loop is if you instead did the air gap. You need one of the two methods in place for the dishwasher to be considered up to code.


The high loop is very easy and quick to install. You simply find the highest point underneath the sink and attach the drain hose to it. There should be at least 32-inches of space between the loop itself and the bottom of the sink. If there is not 32-inches of space, then an air gap will have to be installed instead.

The reason this amount of space is needed is that it makes the loop have a very drastic incline and decline. The big slope makes it hard for water to backflow, though not impossible. The high loop is not a full-proof method but it is much better than not doing anything and risking backflow happening to you.

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How exactly do you secure the drain hose? It can be secured in a variety of ways. It can be secured with zip ties, tape, brackets, or buying an attachment online. Nail a hammer into the back wall to secure the drain hose by using zip ties or tape. Or you can actually purchase brackets where you simply have to attach them to the wall inside the cabinets, then attach the hose to it. When purchased they will come with instructions, though it is very easy to figure out how to do it. They are also fairly cheap and can be purchased in many hardware stores, and even online.

Which One is Better?

The air gap and the high loop are both good options for preventing backflow. The air gap is the most effective solution, making backflow almost impossible. However, it is more expensive and time-consuming. Purchasing the air gap is somewhat expensive, but it is made even more expensive if a professional has to be called in to get the air gap fully installed.

Sometimes calling a professional is recommended if a hole has to be made through the sink to accommodate the air gap. A high loop is much easier and quicker to install, though it is not completely effective at preventing backflow. It’s better than nothing, and most often will work amazingly, For some, it can also just be a quick fix that you may want to improve later on by installing an air gap at some point.

Installing a high loop is also very cheap because you may already have what you need to install it right away without needing to purchase anything. And if you do decide to purchase a bracket, whether simple or slightly more complex, it is still very cheap because a professional won’t need to be called in to do it for you. Both of them are good options, it really just depends on your situation.

Which One to Choose

Are you having trouble figuring out which method to do? The first thing to do is look up your state’s regulations. Some states require the air gap in residential areas. If you live in a state where the air gap is required with dishwashers, then your only option will be to install an air gap. There is simply no way around that.

If it is not required in your state, then you can really do either the air gap or high loop. The air gap is the most effective option, making backflow almost impossible. However, the high loop is much easier to do yourself and cheaper, though not one hundred percent effective. If the air gap is not required, either option will be great to prevent backflow from happening. The decision really comes down to how effective you want the option you pick to be and how much you are willing to risk backflow happening. And it also depends on your situation since some states require certain methods of preventing backflow.