4 Mistakes to Avoid When Installing a Dishwasher

Installing a new dishwasher is an excellent way to simplify daily life, but a poor start can turn a helpful appliance into a persistent headache. Many installation errors are subtle, from uneven mounting to loosely connected drain hose to mounting brackets that are installed wrong. The good news: Most dishwasher installation problems are preventable when you know the right steps and common pitfalls.

We’ve helped customers across the Puget Sound get a smooth start with new appliances for decades, and we’ve seen the same mistakes again and again. Use this guide that outlines four top mistakes to avoid when installing a dishwasher, plus practical, step-by-step fixes, to ensure your new dishwashing machine performs well from day one.

4 Mistakes to Avoid When Installing a Dishwasher

Before we dive into the specific mistakes, let’s explain why installing a dishwasher correctly matters.

For one, a dishwasher that’s properly set up cleans better, lasts longer, and is far less likely to cause water damage or electrical issues. Even small errors made during dishwasher installation can result in noisy cycles, poor drying, dishwasher leaks, or the need for early repairs.

On the other hand, maintenance can be just as important as installation. That’s why regularly leveling your dishwasher and tightening mounting brackets prevents unnecessary wear on pumps and seals, which is key advice on how to extend the life of your dishwasher.

Below are the four most common dishwasher mistakes homeowners often make when installing a dishwashing machine. Follow these and you’ll avoid the common headaches associated with dishwasher setup.

Note: Before fixing any dishwasher problems, be sure to cut the power and water supply to avoid injury.

No Flooring Beneath a Dishwasher

A common mistake for homeowners is not to add flooring beneath a dishwasher. This may save a few dollars up front, but it’s important to have a dishwasher even with a kitchen’s flooring for aesthetics and to avoid damage. Hint: If your dishwasher sticks out, this may be the culprit.

Not to mention, adding flooring one way how to balance a dishwasher. When the dishwasher sits on a different plane than the surrounding floor, it can look awkward, shift under load, and create gaps where water and debris collect.

How to Place Flooring for a Dishwasher

1. Measure the opening: Measure the finished floor height and the opening width and depth. Account for tile, vinyl, or hardwood thickness.
2. Prep the subfloor: If the subfloor is uneven, sand or shim low spots so the finished flooring will be level. Make sure the subfloor is dry and solid.
3. Install flooring to the cabinet line: Lay flooring up to the cabinet toe kick and ensure it reaches the front edge of the dishwasher cavity so the appliance will sit flush. Cut the flooring neatly around the threshold if needed.
4. Allow for expansion: For wood or floating floors, leave the recommended expansion gap and use trim or threshold to cover it to account for expansion during seasons.
5. Test-fit the dishwasher: Slide the dishwasher in to ensure it sits even with the adjacent cabinet face. Adjust the legs as necessary, so the top of the dishwasher is level with the countertop and the flooring is continuous.

Improper Dishwasher Mounting

An improperly mounted dishwasher not only looks wonky, but it can also cause the door to bang your countertop or cabinets. Additionally, a lopsided dishwasher doesn’t clean as effectively, and in extreme cases, pooling water can lead to leaking. Proper mounting secures the unit, protects cabinetry, and prevents the door from tipping the machine forward.

How to Mount a Dishwasher

1. Read the manual: Locate the mounting bracket instructions in the owner’s manual. Different brands mount to the countertop or the side of a cabinet.
2. Level the unit: Use a bubble level front-to-back and side-to-side. Adjust the leveling legs until the dishwasher is perfectly level.
3. Mark mounting points: With the dishwasher partially extended, mark bracket locations on the underside of the countertop or inside the cabinet face.
4. Secure brackets: Attach the supplied brackets to the countertop or cabinet with screws appropriate for the material (use pilot holes for hardwood or particleboard).
5. Slide and fasten: Push the dishwasher fully into place, confirm level once more, then tighten the mounting screws so the unit is snug but not distorted.
6. Check door action: Open and close the door several times to confirm it clears the toe kick and cabinet faces without banging.

Learn More: Albert Lee's Top 10 Dishwashers On The Market

Incorrect Dishwasher Connections

Badly connected dishwasher hoses lead to leaking, while a bad air gap leads to odors escaping. An improperly connected dishwasher is dangerous and will ultimately result in needing to remove the dishwashing machine to properly connect the power source. Proper plumbing and electrical connections are critical to a functioning, safe installation, whereas skipping proper hose installation or failing to level the unit are classic examples of how to ruin a dishwasher.

How to Install Dishwasher Connections

Here are some quick tips regarding how to properly install a dishwasher, starting with how to hook up a dishwasher drain hose and how to hook up a dishwasher water line.

A Dishwasher Drain Hose

1. Route the drain hose from the dishwasher to the sink drain or garbage disposal.
2. Create a high loop under the sink or install an air gap per local code.
3. Secure hose clamps at both ends to prevent leaks and kinking.
4. Tighten connections and run water to test for leaks.

A Dishwasher Water Line

1. Turn off the water supply before attaching the dishwasher inlet.
2. Connect the water line to the dishwasher using a compression fitting or threaded adapter, following the manufacturer’s instructions.
3. Make sure the line is secure and free from kinks, and use plumber’s tape if needed to prevent leaks.
4. Turn the water back on and inspect for leaks while the dishwasher is running a short cycle.

A Dishwasher Air Gap

1. If your code requires an air gap, mount it in the sink or countertop hole provided.
2. Connect the short hose from the dishwasher to the air gap inlet and the longer hose from the air gap outlet to the disposal or drain.
3. Ensure both connections are clamped and upright to prevent backflow and odors.

A Dishwasher Power Plug

1. Turn off the power at the breaker before working on any electrical connections.
2. Depending on the model, either plug into a dedicated outlet or hardwire per the manufacturer’s instructions.
3. If hardwiring, use the provided junction box, secure the connections with wire nuts, and install a strain relief to prevent wire chafing.
4. Restore power and run a test cycle to confirm proper operation.

Wrong Dishwasher Location

Homeowners with kitchen islands need to be certain their current kitchen setup is compatible with a dishwasher in a kitchen island. Otherwise, they will need to either install the dishwasher in the appropriate location or pay to install the proper water and power lines. Placing a dishwasher away from existing plumbing dramatically increases installation complexity and dishwasher installation cost.

When planning placement, evaluate the cabinet layout, proximity to a water supply and drain, and access to electrical. If the appliance will be in an island, make sure there’s room for under-sink plumbing or run new lines professionally rather than improvising. This avoids common issues with dishwasher placement and keeps the installation code-compliant.

Learn More: Fact of Fiction: Five Dishwasher Misconceptions Debunked

DIY vs. Professional Dishwasher Installation

As you prepare to shop for a new dishwasher, you might be asking yourself, “Do I need a plumber to install a dishwasher?” If you have basic plumbing skills, you may opt for a DIY approach to installing a dishwasher. That said, many homeowners choose a professional for peace of mind. Below we outline what’s involved and the typical costs.

The average dishwasher installation cost varies by region and complexity. While a DIY dishwasher install typically costs $100 to $300 for tools, materials, and disposal, hiring a professional typically costs about $100 per hour for labor and takes one and a half to two hours.

Hiring a professional comes with distinct advantages, including:

Code compliance: Professionals ensure the install meets local codes for the air gap, high loop, and electrical wiring.

Leak prevention: Pros use correct fittings and test thoroughly, preventing hidden leaks.

Speed and convenience: Trained installers complete the job quickly and cleanly, with fewer callbacks.

Warranty protection: Many manufacturers require professional install for warranty coverage, and pros can register the install if needed.

Searching "dishwasher installation near me" in the Puget Sound? Count on Albert Lee! We provide the essential parts required to connect your dishwasher to the existing plumbing, and we’ll even haul away your old appliance. Let our technicians handle your dishwasher install  for peace of mind knowing there will be no dishwasher installation problems in the future!

Learn More: Albert Lee's Dishwashers Under $600

Explore Top Rated Dishwashers at Albert Lee

If it’s time to upgrade to a new dishwasher, here are eight of our most popular dishwashers to consider.

Bosch 800 Series Dishwasher 24” Stainless Steel Anti-Fingerprint

Shop This Bosch Dishwasher

The Bosch SHP78DP5N delivers nearly silent operation at 42 dBA while offering the patented CrystalDry system that turns moisture into heat for significantly better drying, especially for plastics. PrecisionWash and intelligent sensors target stuck-on food, so users spend less time pre-scrubbing and more time for enjoyment. The flexible 3rd rack increases capacity and organization for utensils and odd-shaped items, making it ideal for households that value both quiet operation and top-tier drying. If you want an efficient, low-noise machine that handles varied loads well, this Bosch 800 Series dishwasher is a smart choice.

KitchenAid 24” PrintShield Stainless Steel 360° Max Jets Third Rack Dishwasher with Stemware Shield

Shop This KitchenAid Dishwasher

This top-rated KitchenAid dishwashing machine is a standout with 50+ wash jets and a 360° Max Jets third rack that cleans mugs, bowls, and glasses inside and out, reducing pre-rinsing. Its ProDry system and moisture-wicking tines mean dishes come out ready to store, and Stemware Shield protects delicate glasses, which is a perfect feature for entertainers and coffee lovers. True self-cleaning filtration reduces maintenance, and the adjustable racks let cooks fit larger items without sacrificing wash quality. This is a solid pick for buyers who wants high-performance cleaning with and specialized drying tech.

Café 24” Fingerprint Resistant Stainless Steel Top Control Built In Dishwasher

Shop This Cafe Dishwasher

This large capacity dishwasher from Cafe comes loaded features, from its customizable racks and adjustable tines to the Ultra Wash zones made for flexible loading and targeted cleaning. We also love its Dual Convection Ultra Dry feature that provides superior drying, as well as smart features via SmartHQ. Consider this dishwasher if you want smart connectivity alongside heavy-duty cleaning.

GE Profile 24” Fingerprint Resistant Stainless Steel Top Control Built In Dishwasher with Microban Antimicrobial Technology

Shop This GE Profile Dishwasher

GE Profile merges with Microban antibacterial technology for unbeatable protection on touchpoints for a hygienic experience no other dishwasher brands is doing. That’s together with deep clean silverware jets improve usability and performance, Dry Boost for superior drying of plastics, and Active Flood Protect helps prevent costly overflows. Complete with a third rack, steam and sanitize options, this a good fit for tech-forward kitchens that still prioritize reliability.

Samsung 24” Fingerprint Resistant Stainless Steel Built In Dishwasher

Shop This Samsung Dishwasher

Samsung’s Smart Dry with AutoRelease and StormWash+ offer top-tier drying and aggressive cleaning without pre-rinsing. The unit is also whisper quiet at 42 dBA. Features like the Pre Blast Cycle and SmartThings app integration are ideal for busy households that want convenience and strong wash power. The Flex Load Rack system increases usable space, and the overall package suits those who want smart home connectivity plus robust cleaning cycles. It’s a well-rounded option for families and tech-savvy users.

Frigidaire Gallery 24” Smudge-Proof Stainless Steel Top Control Built In Dishwasher

Shop This Frigidaire Gallery Dishwasher

Frigidaire’s CleanBoost and MaxBoost Dry deliver solid cleaning and drying performance, and DishSense sensors reduce the need for pre-rinsing. The third-level rack, target spray zones, and Leak Protection sensor make it convenient and safe for everyday use. With ENERGY STAR certification and water savings, this model appeals to eco-aware households who also want strong cleaning results.

Maytag 24” Fingerprint Resistant Stainless Steel Top Control Built-In Dishwasher with PowerBlast Cycle and PowerDry

Shop This Maytag Dishwasher

This Maytag dishwasher targets heavy-duty messes with the PowerBlast Cycle and PowerDry, plus a large MaxTub for big loads. The 10-year warranty on racks and stainless steel tub parts underscores durability, and features like Quick Cycle and Rapid Sani offer both speed and sanitation when needed. Built for longevity, this is a great pick if you want a rugged machine that handles frequent heavy loads.

Whirlpool 24” Fingerprint Resistant Stainless Steel Built In Dishwasher

Shop This Whirlpool Dishwasher

Whirlpool offers a practical mix of user-friendly cycles, Fan Drying Technology, and flexible rack options that accommodate tall bottles and large pans. The WDT730HAMZ also comes with a Boost Cycle and Extended Soak to help with stubborn soils, while a triple filtration system keeps wash water cleaner. With cycle memory and a focus on durability, Whirlpool fits households that want straightforward operation and consistent results.

Learn More: 7 Most Reliable Dishwasher Models

Dishwashers are heroes in the kitchen, but when they’re improperly installed, they become headaches. Use these tips from our experts to be sure you’re set for the next phase of your dishwasher purchase, and be sure to visit one of our Puget Sound appliance stores for even more dishwasher tips from our experts. While you’re here, explore our top dishwasher picks, plus a full selection of dishwashing machines at great deals!

Why Trust Albert Lee?

Since 1939, Albert Lee Appliance, a three-generation, family-owned business, continues to grow and serve the greater Pacific Northwest with quality products you can count on and service you can trust. We are proud to have served this community for so long and wouldn’t be here without our loyal customers. There is a reason why we are Washington’s largest independent appliance dealer, and it’s not a secret. Simply put: We have the experience. We have been the original appliance experts for over eight decades (and counting).

Shop Dishwashers at Albert Lee

At Albert Lee Appliance, we provide quality name-brand appliances for great prices. Shop dishwashers online or visit us today at one of our six locations in the Pacific Northwest. In the meantime, browse our website to shop Albert Lee appliance sales and check out Albert Lee appliance reviews online to ensure every purchase is an informed one. More available than ever, our experts at Albert Lee Appliance are always happy to help you learn more tips for installing a dishwasher, whether you call us or use our online chat feature. Contact us today!

Learn more: Bosch 800 Series vs 500 Series: Which One Fits Your Needs?

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