What you need to do before you start
Replacing a dishwasher is a project most homeowners can handle themselves if the new unit fits the same space and connects to existing plumbing and electrical lines. The work takes three to four hours and requires basic hand tools—a screwdriver, adjustable wrench, and possibly a utility knife. You will need to turn off the water supply to your kitchen and cut power to the dishwasher at the breaker box before you begin.
Before you buy a replacement, measure the opening where your old dishwasher sits. Standard dishwashers are 24 inches wide, but the height and depth matter too, especially if you have a tight fit under your countertop. Check whether your new unit will connect to the same water inlet, drain line, and electrical outlet as the old one. If the connections are in different places, you may need to hire a plumber or electrician.
Key Takeaways
- Turn off water at the shut-off valve under the sink and cut power at the breaker box before you disconnect anything.
- Disconnect the inlet hose, drain hose, and electrical connector one at a time, taking a photo of each connection so you remember how to reconnect the new unit.
- Remove the old dishwasher by unbolting it from the countertop and sliding it straight out—do not tip it or you may spill water inside the cabinet.
- Slide the new unit into place, reconnect the three lines in reverse order, and run a test cycle with hot water before you push it all the way in.
- If the inlet or drain connections do not line up, or if you have no electrical outlet in the space, stop and call a plumber or electrician rather than improvise.
Shut off water and power
Locate the water shut-off valve under your kitchen sink—it is usually a small knob or lever on the cold-water line coming from the wall. Turn it clockwise (or flip the lever) until it stops. If you cannot find a shut-off valve under the sink, you will need to shut off water to the whole house at the main valve, which is usually in the basement or near the water meter.
Go to your electrical panel and find the breaker that controls the dishwasher. It is often labeled "dishwasher" or "kitchen," but if you are not sure, turn off the breaker and test the outlet under the sink with a lamp or phone charger to confirm the power is off. Flip the breaker to the off position and leave it there while you work.
Disconnect the old dishwasher
Open the dishwasher door and look underneath the front edge for bolts that attach it to the countertop—usually two or three on each side. Remove these bolts with a wrench and set them aside. Do not remove the bolts that hold the door hinges; those stay in place.
Slide the dishwasher out a few inches so you can reach the connections at the back. You will see three things: a water inlet hose (usually connected with a compression fitting), a drain hose (usually held on with a hose clamp), and an electrical connector (usually a plug that looks like a large outlet). Take a photo of each connection before you touch anything.
Disconnect the water inlet hose first by turning the compression fitting counterclockwise by hand or with a wrench. Have a towel ready—there will be a small amount of water in the line. Next, loosen the hose clamp on the drain line with a screwdriver and slide the hose off. Finally, unplug the electrical connector by pressing the release tab and pulling it straight out.
Slide the old dishwasher all the way out and set it aside. If you are removing it from the house, you may need to tip it on its side to fit it through doorways, but do this carefully—water inside the tub can spill into the cabinet space.
Prepare the space and slide in the new unit
Before you move the new dishwasher into place, check that the water inlet, drain, and electrical connections are accessible and line up with where they need to be. If the inlet or drain connections are in a different location on the new unit, you will need to reroute the hoses or call a plumber. If there is no electrical outlet in the space, do not try to run an extension cord—call an electrician to install a proper outlet.
Slide the new dishwasher into the opening slowly and carefully. Make sure the front edge is flush with the cabinet face and that the unit sits level. You can adjust the front legs by turning them clockwise to raise the unit or counterclockwise to lower it. A level unit drains better and runs more quietly.
Reconnect water, drain, and power
Reconnect the three lines in reverse order: electrical connector first, then drain hose, then water inlet. Plug the electrical connector in until it clicks. Slide the drain hose onto the drain port and tighten the hose clamp with a screwdriver—snug but not so tight that you crack the fitting. Hand-tighten the water inlet compression fitting, then use a wrench to turn it another quarter turn.
Before you bolt the dishwasher to the countertop, turn the water shut-off valve back on and the breaker back on. Run the dishwasher through a short cycle with no dishes inside to check for leaks. Watch under the sink for drips from the inlet or drain connections. If you see water, turn off the water and power again and tighten the fitting that is leaking.
Bolt it down and test
Once you have confirmed there are no leaks, turn off the dishwasher and let it drain completely. Slide it back into its final position so the front edge is flush with the cabinet. Insert the bolts through the mounting brackets on the sides of the unit and into the countertop, then tighten them with a wrench. Do not over-tighten—snug is enough.
Run a full wash cycle with a load of dishes to make sure everything works. Listen for unusual noises, check again for leaks under the sink, and confirm that the water drains completely when the cycle ends. If the dishwasher drains slowly or not at all, the drain hose may be kinked or the drain line may be blocked—check the hose path and straighten any kinks.
When to call a professional
If the new dishwasher's water inlet, drain, or electrical connections do not line up with the existing lines, stop and call a plumber or electrician. Trying to extend hoses or improvise electrical connections can lead to leaks, electrical hazards, or damage to your home. If you are uncomfortable working with water lines or electrical connections, or if you encounter unexpected problems during removal, it is safer and faster to hire someone who does this work regularly.
Some older homes have drain lines that empty into a garbage disposal or a standpipe rather than directly into the wall. If your setup is unusual, a plumber can advise you on whether your new dishwasher will work with it or what modifications are needed.
Frequently Asked Questions
Do I need a plumber to replace my dishwasher?
Not if the new unit fits the same space and connects to the same water, drain, and electrical lines as the old one. If the connections are in different locations or you have no outlet in the space, you will need a plumber or electrician to reroute the lines or install new ones.
Can I replace a dishwasher if I rent?
Check your lease and ask your landlord first. Most landlords will not allow tenants to remove or replace built-in appliances. If the dishwasher is broken, contact your landlord to request a repair or replacement.
What if water leaks from under the sink after I reconnect everything?
Turn off the water at the shut-off valve when ready. The leak is usually from the inlet hose connection. Turn the compression fitting another quarter turn with a wrench and test again. If it still leaks, the fitting may be damaged and you may need to replace the hose or call a plumber.
How do I know if my new dishwasher will fit in the old space?
Measure the width, height, and depth of the opening. Standard dishwashers are 24 inches wide, but heights range from 33 to 34 inches and depths from 24 to 26 inches. Check the specifications of your new unit against these measurements before you buy it.
Can I use the old hoses with the new dishwasher?
The inlet hose can usually be reused if it is in good condition and the fittings match. The drain hose should be replaced if it is more than five years old or shows cracks or discoloration. New hoses cost $15 to $30 and are worth the investment to avoid leaks.