How to install a built-in microwave: A step-by-step guide

Before you begin your microwave oven installation, prepare the installation site and assemble your trim or spacer kit (if applicable), then proceed to hooking up and securing your appliance. Always refer to your product’s installation manual for model-specific tools, parts and instructions.

The tools required for built-in microwave installation may vary depending on the model and installation instructions provided in your user manual. Typically, you’ll need:

• Phillips screwdriver

• Measuring tape

• Level

• Drill (for wall cabinet installations)

• 1/8 inch (3mm) drill bit (for wall cabinet installations)

• 1 inch (2.5cm) drill bit (for wall cabinet installations)

If you’re replacing an existing built-in microwave, you’ll first need to remove the old appliance from the cutout with the help of another person. To uninstall your previous model, you may need to consult your owner’s manual to remember how it was installed. Directions may vary by model, but in general, you will be doing the following:

1. Unplug the microwave from the outlet. You may also need to turn off the electrical line from the breaker.

2. Using a drill, unscrew the support screws while another person supports the weight of the appliance.

3. With the help of another person, carefully remove the appliance from the cutout and set the appliance aside.

4. Using a drill, remove any additional mounting hardware and trim.

Consult your user manual to find model-specific fit, trim kit and ventilation requirements for your appliance. You’ll want to confirm:

• The measurement of your appliance

• The measurement of the cabinet opening

• The measurement of any trim or spacer kits

• The model-specific ventilation requirements for your microwave

The electrical supply for the appliance is commonly 240V at 60Hz. A dedicated circuit is required. Be sure to verify these requirements with your product manual and any local code before you begin.

A microwave spacer or filler kit is an accessory designed to securely mount a smaller microwave into a larger space as a built-in appliance. These kits must be compatible with your appliance for proper installation. Follow the specific directions for your corresponding spacer kit. In general, they might look similar to the following:

• First, assemble and install the provided spacer kit, if applicable. With the flange facing outward, align a spacer bar on the bottom trim and secure it with two 3/8 inch washer screws from the provided microwave filler kit. 

• Do the same to align and secure the opposite spacer bar. Now center the spacer assembly against the lower front edge of the cabinet opening. 

• Using a 1/8 inch diameter drill bit, drill through the mounting holes in the spacer bars to create pilot holes. 

• Use a Phillips head screwdriver to thread and tighten the 4 ¾ inch flathead screws from your microwave installation kit to secure the spacer assembly. Avoid overtightening the screws.

WARNING: Electrical shock hazard. Disconnect power before servicing. Replace all parts and panels before operating. Failure to do so can result in death or electrical shock.

Before making any electrical connections, make sure the power supply to the junction box is turned off. If necessary, remove the junction box cover. 

• Use a UL listed or CSA approved half inch diameter conduit connector to connect the flexible cable conduit from the microwave oven to the junction box. 

• Tighten the screw or screws to secure the conduit.

• Now join the black wires together and secure them using an approved, UL listed wire nut. Do the same to secure the two red wires together, and the two white wires. 

• Finally, join the green or bare grounding wire or wires to the bare grounding wire from the microwave oven and secure them with a wire nut. With all of the wires positioned inside the junction box, replace and secure the cover.

If your chosen installation location is not electrically equipped or if you’re not comfortable handling the electrical wiring yourself, schedule an appointment with a licensed technician for assistance. 

Once you’ve prepared your installation location, your appliance is ready to be installed. Use the general steps below in addition to the instructions in your user manual to install your new built-in microwave, as models may vary.

• Using two or more people, align the microwave oven on the spacer bars, if applicable.

• Open the microwave oven door and push against the front frame of the oven to fully insert the appliance into the cabinet.

• Confirm the appliance is centered, then use a 1/8 inch diameter drill bit to drill pilot holes, using the holes in the side mounting brackets as templates. 

• Align the plastic washers with the holes in the mounting brackets, then thread and tighten the two 3/4 inch flathead screws to secure the appliance to the cabinet. Avoid overtightening.

• Replace the glass tray support and the tray as well. Turn the power supply back on, and the microwave oven should be ready for use.

If you’re looking to upgrade your kitchen with seamless integration while enhancing your meal preparation, a KitchenAid^® Built-In Microwave may be right for you. Whether you need to reheat, steam or fully cook a meal, a built-in microwave oven can bring versatility and extra cooking space to your kitchen.

To help you install your built-in microwave so you can enjoy its streamlined look and  enhanced cooking capabilities in your kitchen, read the installation tips below.

• Consider sizing and measurements: Before committing to any drill holes in your kitchen walls, be sure to find the exact measurements and ventilation requirements of the appliance to ensure a correct fit for your microwave oven installation. Also, note the distance of your intended electrical outlet and your microwave power cord length.

• Keep replacement microwave hardware: If you are replacing your current appliance, keep the cabinet screws and mounting brackets after you remove the built-in microwave. The old parts may be used for future repairs for your new unit if your user manual confirms they are compatible.

• Troubleshoot common fit and setup issues: Once you’ve finished installation, take a step back and inspect the appliance. If you notice it isn’t flush with the cabinets, the mounting holes aren’t aligned, the door is rubbing against the cutout or the vents appear blocked, you may need to backtrack and make some adjustments.

• Consider professional help from a technician: An expert can manage the electrical work, measurements and heavy lifting required for installing a built-in microwave. However, if you are set on installing your appliance yourself, keep in mind that the job will take two to three people.

Installing a built-in microwave can be a big task to handle on your own. For help understanding some of the elements of an installation, read answers to the frequently asked questions below.