Replacing a Dishwasher

Replacing an old dishwasher will likely mean significant water savings and quieter operation, and you can save money by eliminating delivery and installation costs. Although bulky, the units are relatively lightweight. The first time you install a dishwasher it typically involves considerable electrical and plumbing skills, but not so with most replacements. Assuming that the original unit was installed properly and according to code, replacing one is well within the reach of most do-it-yourselfers. However, make sure you visit your building department to determine local plumbing and electrical code requirements relating to dishwashers. Improper installations and code changes may require additional steps beyond what you may be willing to undertake.

Your new unit will come with detailed installation instructions, which you should read and follow carefully, but here is an overview of the steps involved and a few tips to make the project a successful one.

Tools & Materials

1. Prepare: Turn off the power to the dishwasher circuit (it must be on its own circuit) at your electrical service panel. Shut off the hot water supply to the unit (typically under the sink if the supply comes from there, but it may also be under the dishwasher or in the basement if the supply comes through the wall or floor of the dishwasher opening). Remove the access and lower panels at the base of both dishwashers.

2. Disconnect Wires: Remove the electrical terminal box covers on both units and disconnect the wires on the old unit. Twist off the connectors and unscrew the ground connector. Then loosen the nut on the strain-relief connector (the device that clamps the cable to the box) by tapping the nut with the tip of a flat-blade screwdriver.


3. Disconnect Drain: Disconnect the drain hose from the waste tee on the drain line, or the inlet on a disposer, using pliers to open a spring clamp or a screwdriver to open a screw-type clamp. Do the same where it connects to the dishwasher. If you can't easily access that connection, you can disconnect it later.

4. Disconnect Water: Use an adjustable wrench to disconnect the water supply line from the water inlet on the dishwasher (typically a 90-degree elbow fitting). To avoid damage to the water inlet valve or other connections, grasp the elbow with a pipe wrench and apply counterpressure.


5. Remove Dishwasher: Open the door to access and remove the screws that secure the dishwasher to the underside of the countertop. Then adjust the front leg levelers to lower the unit so you can slide it out. Be careful to avoid getting caught on plumbing and electric lines.


6. Check Compatibility: Compare the location and type of connections on the dishwashers to verify that the existing wires and drain and water lines are long enough and correctly positioned for the new unit. These requirements should be spelled out in the installation manual. Typically, the only problem might be with the water line if you are changing brands.

7. Move Water Line: If necessary, relocate the water line. You can usually bend tubing with your hands as needed but be careful not to kink it; if you cannot, replace it from the valve connection. Rigid pipe must be rerouted by cutting into it and installing new fittings and pipe, or by replacing it from the valve. The procedures vary according to the material. Typically only basic plumbing skills (such as tube cutting, soldering) and additional tools (such as propane torch and solder) are required.

8. Place Unit in Opening: Measure the height of the opening and follow the manufacturer's instructions to prepare the unit for installation. Depending on the height of the opening and the brand of your machine, you may need to move rear wheels into different mounting holes and attach the drain line. Close and lock the door, then slide/roll the machine to the opening so you can feed the drain hose into the sink cabinet. Now slide the unit into the opening.

9. Level the Machine: Adjust the leveling legs as indicated by the manufacturer to raise the dishwasher. Use a level to verify that the unit is level. Install the mounting screws into the underside of the counter. Solid-surface or stone counters require that screw anchors be installed into drilled holes.



10. Make Connections: Reverse the removal procedures to connect water, drain, and electric lines. Cut off the exposed ends of electrical wires and use wire strippers to strip about 1/2 inch of insulation from the ends. Twist wires together (white-to-white, black-to-black) and twist on new wire connectors. Secure the ground (green) wire. Tighten the strain-relief connector.

11. Install Decorative Panels: Your new dishwasher may have a reversible or replacement front panel that enables you to change the color to match other appliances, or may accept a panel that matches your cabinets. If so, remove the frame screws as directed to change or install the panel. Reinstall screws.

12. Adjust Door: Follow the manufacturer's instructions to adjust the door so there is an even space on both sides. You might, for example, need to move the door spring to a new mounting hole.

13. Test Operation: Open the water valve to check for leaks in the water line at valve and inlet connections. Restore power and operate the machine to check for drain leaks. When all is well, reinstall the lower panel and front access panel.

 

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