How to Install a New Dishwasher (or Replace an Old One)

Things You’ll Need

  • Wrench
  • Drill
  • Screwdriver
  • Thread seal (Teflon) tape
  • Dual outlet valve
  • Right angle elbow
  • Dishwasher drain tailpiece
  • Plumber’s strapping
  • Tape
  • Air gap (optional)


How to Repair Your Dishwasher – The Spruce

While it may seem like an intimidating appliance, a dishwasher is, at its heart, a simple device that you can repair on your own. Understanding how your dishwasher works will help you repair the machine smoothly and safely. Your dishwasher heats water as high as 140 F in its lower basin (the area below the bottom rack) with a metal heating element.

Seen 161 times

More Reviews ››

Replace dishwasher with clothes washer

 · I have a dishwasher I barely use in my home. My washer and dryer are located in a detached garage and it becomes a pain in the winter to go back and forth from the main home. I was wondering how easy/difficult it is to remove a dishwasher and replace with a clothes washer (if I can find one the same size). I am happy to line dry my clothes.

Seen 116 times

More Reviews ››

How to Fix a Dishwasher That Will Not Drain

When the dishwasher does not drain or drains slowly, your machine probably has a blockage that you can clear by hand.

  1. Check the Sink and Drain Tube

    Look at the kitchen sink first. Your sink and dishwasher share a common drainage system. If the dishwasher drain is clogged, the sink might be, too.

    While under the sink, verify that the dishwasher’s drain tube (a corrugated plastic tube) is not kinked. It should run in a smooth curve from the dishwasher to the drain.

  2. Inspect and Clean the Drain Filter

    Check out your dishwasher drain filter at the bottom of the machine, in the basin. Some food particles pass through the filter, but it is designed to block larger particles. Clear the filter by pulling the particles out (do not force them into the filter).

    If there are no visible particles, remove the filter cage by removing the two screws from the top of the cage. After removing the cage, clear any blockages.

  3. Clear the Drain Tube

    Shut down and remove the machine. Locate the plastic drain tube attached to the back of the machine. Detach it and blow into the tube. If air does not flow freely, the tube is blocked.

    Clear the tube by forcefully running water into it in a sink. If the block is difficult to clear or the tube appears damaged, purchase a new one.

Valve, Dispenser, and Dish Rack Repairs

Checking on and routinely maintaining the various valves, detergent dispenser, and dish rack can keep the right amount of water and cleaner working effectively in your dishwasher.

Servicing the Water Inlet Valve

The water inlet valve controls the amount of water flowing into the dishwasher. It may be activated by the timer or by a solenoid. If the dishwasher doesn’t fill with water:


Step 1: Make sure that the water supply to the unit is turned on and that there’s no problem at the water heater. A shutdown of the water heater would cause a shutdown of the water to the dishwasher.

Step 2: Check the timer to make sure it’s working through its programmed sequences. If both the water supply and the timer are in working order, the problem is probably in the inlet valve.

Step 3: Check the inlet valve located under the tub of the dishwasher. Malfunctions of the inlet valve may also occur when a screen inside the valve becomes clogged with mineral deposits. To solve this problem, pry out the screen with a screwdriver and flush it thoroughly with running water. Then replace the screens.

Step 4: If the valve is controlled by a solenoid, the solenoid is usually connected to the side of the dishwasher. Tap the solenoid and the valve lightly with the handle of a screwdriver to break it free of any obstruction. Then start the dishwasher again.

Step 5: If the dishwasher still doesn’t fill, test the solenoid with a volt-ohm-milliammeter (VOM) set to the RX1 scale. Disconnect one electrical lead to the solenoid and clip one probe of the VOM to each solenoid terminal. If the meter reads from about 100 ohms to 1,000 ohms, the solenoid is functioning. If the reading is higher than 1,000, the solenoid is faulty and should be replaced.

Step 6: If necessary, replace the solenoid with a new one of the same size and type. Connect the new solenoid the same way the old one was connected.

Badly worn or misshapen inlet valves cannot be repaired. If the valve is damaged, replace it with a new one made for the dishwasher. The valve is usually held to a mounting bracket with screws. Take apart the connection linking the valve to the water supply. Then take out screws and remove the valve. Install the new valve by making the connections in reverse order.


Step 2: Disconnect the electrical cable and water line

Photo 1: Remove the front panel

Photo 1: Remove the front panel

Turn off the power, remove the front panel and use a voltage tester to make sure the power is off. Disconnect the wires and pull the cable from the box. Wiring the dishwasher will come later. 

Photo 2: Disconnect the water supply

Photo 2: Disconnect the water supply

Remove the compression fitting nut from the water supply line (water turned off). Note which way the 90-degree elbow points, then unscrew it.

Photo 3: Disconnect the drain

Photo 3: Disconnect the drain

Slide the dishwasher drain tube off the inlet arm on the sink drain. Drain it into a bucket. Remove the screws securing the dishwasher to the countertop.

Photo 4: Pull the dishwasher out Lower the dishwasher and slip cardboard under the feet. Then gently lift and slide the dishwasher out. Work the drain tube out through the side of the cabinet.

The water and electrical connections are underneath the dishwasher, behind a lower front panel that you have to unscrew (Photo 1). Always test with a voltage detector to make sure the power is off. When you remove the electrical line from the box, leave the cable clamp on and reuse it on the new dishwasher(Photo 12). Sometimes dishwashers are plug-and-cord connected rather than “hard wired” as shown in our photos. If so, disconnect the cord and reuse it on the new dishwasher. If it’s in bad condition, buy a new one from an appliance dealer.

Usually, the water supply line is flexible copper or braided stainless steel. In either case, remove the nut securing it to the 90-degree fitting on the dishwasher (Photo 2). As long as the nut and ring are in good condition (no nicks or gouges; Photo 11), leave them on the line for later reuse. You can bend the copper line slightly, but take care not to kink the line. If you do, you’ll have to replace it. Flexible stainless steel lines are a good replacement. They are available at a hardware store or home center. Make sure you buy them long enough and with fittings that match the old.

Remove the 90-degree fitting for use on the new dishwasher. It’s important to orient it exactly the same direction on the new machine so that the water line feeds directly into it. Otherwise you might kink the line.

Sponge out any standing water inside the dishwasher before removing the drain line under the sink. It’s the flexible hose that’s clamped to an inlet arm on the sink drain or a garbage disposer (Photo 3). As you slide the old dishwasher out, you’ll have to simultaneously work the drain hose back through the hole in the sink cabinet. Keep a rag handy to wipe up the water that’ll run out of the line.

Lowering the dishwasher gives you more clearance to slide the dishwasher out. Chances are the leveling feet will be difficult to turn, but a shot of penetrating oil on the threads may make it easier. If you need more clearance, cut the feet off with a hacksaw blade and turn the screw out. Then be sure to slip cardboard or a rug under them to avoid gouging your floor when you pull out the dishwasher.


1. Turn off the electricity to the dishwasher at the main electrical panel. 2. Remove the access panel from the lower front of the dishwasher and disconnect the electrical wiring. 3. Turn off the water to the dishwasher at the shut-off valve. 4. Disconnect the copper water-supply line from the dishwasher; drain excess water from the line into a shallow pan. 5. Disconnect the drain line from the dishwasher. 6. Open the dishwasher and back out the screws holding it to the underside of the counter. 7. Slide out the old dishwasher. 8. Drill 1-inch hole through cabinet; feed soft copper tubing through hole into sink cabinet. 9. Use adjustable wrench to attach copper tubing to hot-water shut-off valve inside sink cabinet. 10. Disconnect old drain line from the garbage disposer. 11. Tape hot-water line and electrical cable to floor; slide new dishwasher into place. 12. Bend the copper line using a tubing bender. 13. Cut tubing to length and attach it to the dishwasher with a compression fitting. 14. Secure electrical wiring with twist-on wire connectors. 15. Use stainless-steel hose clamp to connect new drain hose to side of garbage disposer. 16. Screw dishwasher to underside of countertop.

Step 4: How to hook up a dishwasher and reconnect it

Photo 8: Slide the new dishwasher in

Photo 8: Slide the new dishwasher in

For how to install a dishwasher, grasp the sides of the dishwasher, lift slightly and roll the dishwasher into the opening. Protect the kitchen floor with a tarp or cardboard.

Photo 9: Align the dishwasher

Photo 9: Align the dishwasher

Slide the dishwasher back until it’s flush to the cabinets. Positioning may vary slightly according to dishwasher styles and the style of your cabinets.

Photo 10: Level the dishwasher

Photo 10: Level the dishwasher

Adjust the leveling feet with a wrench until the dishwasher is level (side to side) and plumb (up and down).

Photo 11: Attach the dishwater supply line

Photo 11: Attach the dishwater supply line

Align the dishwasher water supply line so it slides straight into the 90-degree fitting. Thread on the compression nut (no Teflon tape needed) and tighten with a wrench.

Photo 12: Finish the drain and electrical connections Clamp the dishwasher drain hose to the dishwasher. Then clamp the electrical wires and connect them. Finally, screw the dishwasher to the countertop bottom.

For how to install a dishwasher, slide the new dishwasher in (Photo 8), grasping it by the sides to avoid denting the front panel. Set the dishwasher in position according to Photos 9 and 10. But don’t secure it to the countertop yet. Wait until you make all connections and adjustments.

How to install a dishwasher involves connecting the copper water line so it doesn’t leak can be tricky. The secret is to align it so it slides straight into the threaded part of the elbow (Photo 11). If it’s cocked to one side, the compression nut won’t thread on right and it’ll leak. If necessary, turn the elbow on the dishwasher slightly with a wrench to align it, or gently bend copper lines about 8 to 12 in. from the end.

With the dishwasher water supply line, the electrical cable and drain connected, turn the power and water back on and check for leaks. Recheck the positioning, then screw the dishwasher to the countertop (some screw to the cabinet sides). If your countertop is a synthetic material or stone, and the old holes don’t line up, follow the directions listed in the manual on how to install a dishwasher.

Caution If you have aluminum wiring, call in a licensed electrician who’s certified to work with it. This wiring is dull gray, not the dull orange that’s characteristic of copper.

Disassembling the Dishwasher

Access to the working parts of most dishwashers is through the front door of the unit. Many repairs can be made to the machine by simply opening the door and reaching into the various component parts, such as the sprayers, strainers, float switch, racks, and door latch.

To get to the control panel on the door, remove a series of retaining screws around the panel. These screws may be under molding trim strips, which usually snap onto the metal housing. Pry off the strips with a stiff-bladed putty knife or a screwdriver, or remove a setscrew that holds the molding. The control knobs are friction-fit on shafts or are held by small setscrews in the base of the knobs. In some dishwashers, the entire front door panel must be removed to gain access to the control components. This panel is held to the door by a series of retaining screws, usually found around the edge on the inside back of the door.


On many models, once the control panel is removed the door panel can be removed by unscrewing a series of fasteners holding the door panel in place. Sometimes these retaining screws are covered by trim moldings, which must be pried or slipped off. For access to the motor, pump, hoses, inlet valves, and other parts, remove the lower access panel. This can usually be done without removing the entire door. The panel may be held by retaining screws, or it may lift up and off metal hangers.

If the dishwasher is portable, tip the machine over on its back or side before removing the control door or lower access panels. This may give you a more comfortable working position.

Once you can get inside the dishwasher, knowing the major parts and how they function will help you assess the problem. We’ll review the main parts and how to check them in the next section.


Sign up for the Newsletter

Get the latest This Old House news, trusted tips, tricks, and DIY Smarts projects from our experts–straight to your inbox.


Leave a Reply

Your email address will not be published. Required fields are marked *

Go up