Do I Need A Garbage Disposal With A Dishwasher?

Modern appliances simplify various activities: washing dishes, cooking food, disposing of food scraps, etc. Garbage disposals and dishwashers are two common appliances in many kitchens, going hand in hand. In many cases, the two meet and share plumbing, making the installation easier. 

However, can you install a dishwasher without a garbage disposal? If you plan on installing a dishwasher or garbage disposal soon, this may be a point of concern. This article will answer these questions and clear up any confusion surrounding the topic, so stick around to learn more!

Do All Dishwashers Have A Garbage Disposal?

No, not all dishwashers have a garbage disposal. With that said, many American-made dishwashers feature a built-in water garbage disposal. European models tend to have filtration systems to purify the food particles from the drainage water. 

Built-In Garbage Disposals


Nowadays, most dishwashers come in one of two varieties: with a filtration system or built-in garbage disposal. Major American-made brands, like KitchenAid, Whirlpool, and GE, come with hard food disposers. These disposers are essentially mini garbage disposals, with a lower grinding capacity and motor power than their larger comrades.

Usually, these disposers can’t handle the same amount of food waste as their larger counterparts since they don’t have the capacity or motor power to handle the excessive waste.

The built-in garbage disposal allows people to simply scrape excess food from dishes, then add them to the dishwasher. The dishwasher takes care of the rest, disposing of small food particles entirely. 

Due to the added appliance, these dishwashers make more noise. Although the noise is relatively quiet compared to a full-size garbage disposal, they still produce some noise. Of course, noise levels vary from one brand to the next, but the noise is typically like softer background noise.  

Filtration Systems

European Dishwasher

Unlike American-made dishwashers, European dishwashers usually feature filtration systems. Many of these manufacturers believe the addition of a garbage disposal is entirely unnecessary. So, instead of a garbage disposal, these appliances usually have a filtration system.

The high temperatures produced by the appliance during the washing process helps break down food particles, which then are intercepted by the filtration system. Although you don’t have the extra noise that a garbage disposal would produce, you have to check the filters regularly. 

Depending on how often you use them, “regularly” could be once every ten days or once a month. It ultimately depends on how often you use the appliance. However, failing to check the filters regularly could lead to clogs along the drain lines, which creates all sorts of issues. 

Separate Appliances

However, in terms of two entirely separate appliances, no, not all dishwashers have a garbage disposal. Generally, if you have both appliances, the dishwasher line hooks up to the side of the garbage disposal. The connection enables the two to share plumbing. 

Many homes have dishwashers, but not all have garbage disposals. Although garbage disposals are a staple in many kitchens, they aren’t feasible in all scenarios. For example, garbage disposals can interfere with the biology in a septic tank, so they’re less common in homes with septic tanks. 

How Do You Hook Up A Dishwasher Without A Garbage Disposal?

How Do You Hook Up A Dishwasher Without A Garbage Disposal

Although dishwashers usually connect to a garbage disposal, providing there’s one present, it isn’t necessary. You can easily bypass the appliance with specific piping attachments. 

If you don’t have a garbage disposal with your dishwasher, you must include an air gap within the new dishwasher installation. This ensures the appliance is in agreement with local plumbing codes and regulations. 

The Uniform Plumbing Code Section 807.4 states, “no domestic dishwashing machine shall be directly connected to a drainage system or food waste disposer without using an approved dishwasher airgap fitting on the discharge side of the dishwashing machine.” 

The dishwasher’s hose must run down from the air gap (or high loop) and join the sink drain via a drain tailpiece with a branch fitting. The hose fits onto the ribbed branch fitting, then is secured with a hose clamp. 

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For everything to function correctly, the dishwasher hose must connect to the sink drain before the drain’s P-trap. If it connects to the drain after the P-trap, there may be a backflow of sewer gasses into the dishwasher hose and into the dishwasher. 

This doesn’t bode well for clean dishes, so it’s essential to secure the hose to the correct spot. Since a dishwasher drains into your kitchen’s plumbing system, there’s a possibility of dirty water siphoning back into the appliance and contaminating clean dishes or the freshwater supply. 

Dirty, contaminated water has no place in a clean dishwasher, so installing the proper plumbing is an integral part of the process. If you’re not familiar with plumbing projects, it may be best to hire a plumbing to handle the process. Installing a dishwasher without a garbage disposal requires some know-how with circuits and plumbing. 

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