Why does a dishwasher have to drain through the sink plumbing?

• <div><p>Any drain in your house requires a water trap to prevent sewer gases from entering the home. Dishwashers don’t have an internal water trap, so they must use an external P trap. The most convenient P trap for the dishwasher is already in the plumbing under your sink.</p></div>

Get matched with top dishwasher installation pros in Onley, VA

Q: Does a dishwasher need an air gap?

• <div><p>Yes, a dishwasher needs an air gap to prevent backflow. Additionally, in many locations, air gaps or another measure to prevent backflow are required for building code compliance. There are alternatives to an air gap, like a Studor vent or a loop and trap design, but an air gap is the simplest and most popular solution. </p></div>

Q: Can an air gap cause a dishwasher not to drain?

• <div><p>A clogged air gap can cause a <a href="https://www.angi.com/articles/why-wont-my-dishwasher-drain.htm">dishwasher not to drain</a>. There are, however, other potential issues that can lead to improper drainage. For example, if you have attached the air gap to a garbage disposal and forgotten to remove the knockout plug, wastewater may backflow into the dishwasher. Check that the air gap is installed properly, and then look for clogs in the air gap and dishwasher filters. </p></div>

Q: Why is professional installation or repair important for dishwashers?

• <div><p>Professional services ensure correct installation, verify water-tight seals, and safely address plumbing and electrical connections in dishwashers.</p></div>

Q: Can I repair my dishwasher myself?

• <div><p>Basic maintenance, such as cleaning filters, is DIY-friendly, but repairs involving electrical components, pumps, or valves should be handled by a professional.</p></div>

Enter your zip and get matched with up to 5 pros

Need a pro for your dishwasher installation project in Onley, VA?

Select your specific project to find the pro for you.

Verified Reviews for Dishwasher Installation pros in Onley, VA

*The Angi rating for Dishwasher Installation companies in Onley, VA is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Dishwasher Installation needs.

*The HomeAdvisor rating for Dishwasher Installation companies in Onley, VA is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Dishwasher Installation needs.

Last update on August 12, 2025

Reviewed in August 2025
Ismar and his team arrived on time, were polite, and treated our home with the utmost respect. Our bathroom exhaust fan was installed with great professionalism, and the cost was very reasonable. We are absolutely thrilled with the result. We will certainly turn to them for future remodeling...
Ismar Remodeling
Request a quote
Reviewed in May 2025
Bay did and encapsulation for us earlier this year. We have an old house and, not surprisingly, needed some follow up work doneand one of the dehumidifiers they installed replaced under warranty. Once again, their crews - Mike, Maine, Angel, Josh and Aaron, were all terrific. They were on time,...
BAY Crawl Space & Foundation Repair
Request a quote
Reviewed in March 2025
We actually had a couple of roofs put on. The whole process from initial inspection and price negotiation to final install was amazing. Mark Johnson the project manager was absolutely fantastic. The install team found a couple of issues after they did the tear off. The problems were fixed...
Home Genius Exteriors
Request a quote
Reviewed in May 2024
DGL is highly recommended for exhibiting and performing all the attributes and expertise one would look for when hiring a contractor. He has completed several jobs for me including carpentry work, fireplace insert installation, renovation of old patio and installation of new bluestone one,...
DGL GENERAL CONTRACTING, LLC.
Request a quote
Reviewed in March 2024
New water line was well installed and affordable.
Rooter ProXpress LLC
Request a quote
Reviewed in April 2022
We hired Window World to do 2 jobs. One was an asphalt shingle roof and that went well. Crew arrived when they were supposed to and completed the job within 2 weeks of signing the contract. The second job was to install new vented soffits and wrap the facia with aluminum coil as well as...
Window World of Delmarva, Inc.
Request a quote
Reviewed in February 2022
Matt and Tyler were a fantastic team. They arrived on time. Removed the existing antiquated bath/tub and installed a new step in shower. It looks amazing. They kept the place clean as they worked. At the completion everything was reviewed and instructions provided where requested. My home...
West Shore Home Virginia Beach
Request a quote
Reviewed in December 2017
Jeff did a great job repairing my vinyl siding and installing a mounting plate for a light fixture over my garage. The work was done timely and completed quickly. He was very professional and arrived when he said he would.
Quality Contracting
Request a quote
Reviewed in November 2017
They do excellent work. They do their own plumbing, electrical work, and painting, so you don't need to wait for subcontractors to show up. Only the tiles and cabinets were installed by others. The crew leader is also great to work with. After four years in our kitchen, everything is solid as a...
Ed Weber Contracting
Request a quote

Find Dishwasher installation pros in Onley

No results for Dishwasher installation pro in

Try adjusting your search criteria.

Dishwasher Installation questions, answered by experts

Yes, a dishwasher needs an air gap to prevent backflow. Additionally, in many locations, air gaps or another measure to prevent backflow are required for building code compliance. There are alternatives to an air gap, like a Studor vent or a loop and trap design, but an air gap is the simplest and most popular solution.

A clogged air gap can cause a dishwasher not to drain. There are, however, other potential issues that can lead to improper drainage. For example, if you have attached the air gap to a garbage disposal and forgotten to remove the knockout plug, wastewater may backflow into the dishwasher. Check that the air gap is installed properly, and then look for clogs in the air gap and dishwasher filters.

Any drain in your house requires a water trap to prevent sewer gases from entering the home. Dishwashers don’t have an internal water trap, so they must use an external P trap. The most convenient P trap for the dishwasher is already in the plumbing under your sink.

Professional services ensure correct installation, verify water-tight seals, and safely address plumbing and electrical connections in dishwashers.

Basic maintenance, such as cleaning filters, is DIY-friendly, but repairs involving electrical components, pumps, or valves should be handled by a professional.

The Onley, VA homeowners’ guide to dishwasher installation services

From average costs to expert advice, get all the answers you need to get your job done.

See all articles

Angi
•
Apr 6, 2026Apr 6, 2026
How Much Does Dishwasher Installation Cost? [2026 Data]
Discover the average dishwasher installation cost, key price factors, and tips to save on your project. Get transparent, expert-backed estimates.
Heather Ayer
•
Jul 8, 2026Jul 8, 2026
How Much Does a Dishwasher Cost?
Whether you’re replacing an old dishwasher or buying your first, find out more about dishwasher costs, including new dishwasher installation.
Amy Freeman
•
Jul 10, 2026Jul 10, 2026
How to Install or Replace a Dishwasher
You don’t always need a pro for appliance installations. Use this guide to learn how to install a dishwasher on your own.
Kate Fann
•
Jul 9, 2026Jul 9, 2026
Who Do You Hire to Install a Dishwasher?
Before upgrading to a new dishwasher, you need to know who to hire to install the dishwasher, as your choice can impact its efficiency and safety.
Kate Fann
•
Jul 9, 2026Jul 9, 2026
5 Types of Dishwashers and How to Choose One For Your Home
Overwhelmed with dishwasher options? Learn about the different types of dishwashers to increase efficiency and space in your kitchen.
Kyle Schurman
•
Jul 9, 2026Jul 9, 2026
Parts of a Dishwasher: Learn What They Are and How They Work
Understanding the different parts of a dishwasher can help you troubleshoot any issues and know when to call in the professionals.