Replacing an over-the-range microwave is not as difficult as it may seem. You will need someone to assist you with lifting the microwave and the appropriate tools for the installation. Typically, you will need a Phillips-head screwdriver, a level, a drill, tape, and a stud finder. Most over-the-range microwaves come with templates that will assist with the installation and instructions for the specific drill bits that are required. Once you have the tools you need, you should be able to follow this guide and install your new microwave.
These are generalized steps and the process can vary by model and brand.
To guard against electrocution, it is recommended that you first turn off the power supply to the microwave’s power outlet in your electrical panel.
Uninstall the Old Microwave
- Unplug the microwave from the power outlet.
- Empty the microwave, removing the turntable plate and turntable support.
- Have someone help hold the microwave as you remove the screws that secure the microwave from the top of the cabinet.
- If your microwave has screws holding it to the mounting plate, unscrew them. Make sure someone is helping to support the microwave while removing the screws.
- With someone helping you, tilt the microwave away from the cabinet, take it off the mounting bracket, pulling the power cord through at the same time, and set the microwave down.
Remove the Previous Mounting Bracket
If your new microwave is the same brand as the old one, you may be able to reuse the existing mounting bracket. It is best to check the specifications carefully, as a newer model may still require a different mounting bracket.
- Remove the screws that hold the old mounting bracket in place. If you find the bolts spin in place when you try to remove them, they are likely toggle bolts. To remove toggle bolts, you can place a putty knife behind the head of the bolt and pull it toward you as you remove the bolt. The toggle bolt should then fall into the wall cavity.
- Take the old mounting bracket off the wall and set it down.
Unbox the New Microwave
- Most new microwaves will come with instructions for unpacking the microwave on the box. Make sure to follow these instructions, gently rotating the microwave so that the box is upside down and you can pull the box up off the unit.
- Unscrew the mounting bracket from the back of the new microwave. After configuring the blower system, the mounting bracket will be secured to the wall.
Configure the Blower System
Before installing the microwave, you need to align the microwave blower system with your exhaust. Depending on where your exhaust vent is, you will need to rotate the blower system to either face the rear or top of the appliance. If you do not have an exhaust duct, you should align the blower system toward the front.
- Use a Phillips-head screwdriver to remove the screws securing the damper plate to the top of the microwave oven exterior.
- Slide the damper plate toward the front of the appliance to remove it.
- Remove the screws that secure the blower motor to the back of the microwave oven.
- Lift out the blower motor and rotate it so that the vent ports face up to allow for roof venting, or rotate the blower to position the ports toward the rear of the appliance for wall venting. If you do not have an exhaust duct, rotate the blower motor to position the ports toward the front. If you need to disconnect the wire connector, do so, and then reconnect it once the blower motor is positioned correctly.
- If preparing the microwave for wall venting, you may need to use wire cutting pliers to snip out the damper vent covers on the rear of the microwave.
- When the blower motor is correctly positioned, rethread and tighten the screws to secure the motor.
- Reattach the damper plate, making sure the tabs are inserted into the slots at the top of the appliance, and rethread and tighten the damper plate screws.
- If the microwave requires wall venting and you have a damper assembly, you can now install the damper assembly to the back of the microwave. Make sure the blade hinges at the top and opens outward. The damper assembly should open to allow the fan to exhaust and close when it is not in use. For roof venting, it is usually best to wait until the microwave is mounted before attaching the damper assembly to the damper plate.
Install the Mounting Plate
- The microwave oven must be installed on at least one wall stud, although two is preferred. Lag screws should be used to secure the mounting bracket to the stud. A stud finder can be used to locate the wall stud or studs; then mark where the studs are located.
- Use a measuring tape to determine where the center of the opening is and mark the centerline on the wall to help with positioning the new microwave correctly.
- Your microwave should have come with a template to help position the mounting screws. Line up the template on the back wall with the centerline you marked previously. Check that the template is level, and then use tape to secure the template to the rear wall. If there is no template, follow the manufacturer’s instructions to lay out the mounting holes.
- Mark both mounting holes in the lower corners, and then remove the template.
- Align the mounting plate using the markings, and mark the hole or holes that align with the wall stud or studs.
- Use an appropriate drill bit to drill where the holes are marked. Make sure that at least one screw will be secured to a stud and that you use a lag screw.
- Toggle nuts, which grip the drywall, are used to help secure the mounting bracket where there is not a wall stud. Insert the round-head bolts through the end holes of the mounting plate, and begin to thread on the toggle nuts.
- Realign the mounting plate and use the lag screw, round-head bolts, and toggle nuts to secure the mounting plate to the wall.
- Confirm the mounting plate is level; then tighten the screws and bolts.
Prepare the Upper Cabinet
The upper cabinet requires holes for the power cord and mounting screws. You may be able to use the existing holes in the upper cabinet, particularly to fit the power cord through. Use the upper cabinet template to check where the holes need to be.
- Use tape or thumbtacks to secure the upper cabinet template against the bottom of the cabinet. Make sure the centerline on the cabinet aligns with the centerline on the wall.
- If required, drill the power cord access hole through the bottom of the cabinet as indicated on the template.
- Next, if required, use the appropriate drill bit to drill the holes for the cabinet mounting bolts as indicated on the template. Once completed, remove the template.
- Slide a washer over each flathead mounting bolt, and place the bolts and washers in the cabinet near the holes.
Installing the Microwave
It is recommended that you have someone help you with this process. You may also want to tape the microwave door shut to prevent it from opening while installing the microwave.
- With someone helping you to lift the microwave, lock the back of the microwave onto the mounting plate’s support tabs; then feed the power cord through the hole in the cabinet.
- With someone holding the microwave in place, thread the mounting bolts through the upper cabinet and into the top of the appliance.
- Tighten the mounting bolts; then check that the microwave is secured correctly.
- If applicable, attach the filters underneath the microwave oven.
- Plug the power cord into the electrical outlet, and turn the power back on.
- Position the microwave turntable and turntable support inside the microwave.
- Test the microwave to make sure it is working correctly.