How to Install an Over-the-Range Microwave

1. Find the Studs

   The mounting strip that supports the back of the microwave needs to be secured to wall studs, not simply the wallboard. Begin by using a stud finder to locate the studs in the space below the upper cabinet. Then, use a level to extend the lines downward on the wall, marking them with a pencil.

2. 
   Apply the Paper Template to the Wall

   Your microwave should have two paper templates: one to apply against the back wall and another to tape to the bottom of the upper cabinet. Apply the wall template to the wall with masking tape.

3. Drill Pilot Holes
   

   Using the template as a guide, find at least two stud locations, if possible, that correspond to attachment points on the template. Drill pilot holes at these locations with a drill bit that is slightly smaller in diameter than the mounting bolts or screws.

4. 
   Apply the Paper Template to the Cabinets and Drill Holes

   Apply the second template to the bottom of the upper cabinet with masking tape. This template will show you where to drill holes for power cords and venting. Drill these holes at the indicated locations with a spade bit. You will also drill holes for the oven's mounting bolts at the indicated locations.

5. Cut Openings for the Vent

   The location for your vent will depend on if the existing vent runs up through the roof, or through the back wall behind the oven. Use a jigsaw to cut an opening in either the back wall template or the bottom of the upper cabinet, depending on how the vent and ductwork are configured. Remove the template from the cabinets after cutting.

   Tip

   You may need to add a vent collar, transition fitting, or make other adjustments to the oven's venting feature before lifting the oven up into place.

6. Install the Mounting Bracket

   Remove the template from the wall. Position and mount the metal mounting bracket on the back wall. Use your pilot holes and follow the manufacturer's directions. Ideally, the strip should be anchored at stud locations. It's vitally important to anchor it to at least one. Where it is not possible to anchor to at least two studs, the manufacturer may provide instructions for using alternate wall anchors to attach the bracket.

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7. Position the Microwave Oven

   With the assistance of a helper, lift the microwave into place, feeding the electrical cord up through the drilled hole in the upper cabinet. Have your helper hold the bulk of the weight while you reach around back and hook the oven's slots over the tabs on the metal mounting bracket. Have your helper hold the oven up against the upper cabinet as you quickly move to the next step.

8. Attach the Top Mounting Bolts

   Your microwave's installation kit should come with self-aligning mounting bolts. With your partner still steadying the microwave, go above into the upper cabinet and thread the bolts down through the drilled holes and into the chassis of the oven. As soon as they are threaded, your helper can carefully let go. Tighten screws the rest of the way with a wrench. As you tighten, use a level to make sure the oven is perfectly horizontal.

9. Connect the Duct

   If your microwave is being vented through ductwork, connect the oven's vent outlet to the ductwork. Some form of transition fitting may be needed; if necessary, use tin snips and metal screws to shape and secure the pieces together. Seal all joints with metal tape. (Do not use standard duct tape for this.)

   Plug in the oven and test its operation.

When to Call a Professional

The installation will be relatively easy if there is access to an electrical outlet in the space above the microwave, and if there is an existing vent duct running through the sidewall or up through the roof. If that's not the case, then you may find the project complicated by the need to install a new electrical circuit and to run new ductwork and an exterior vent. At this point, the project shifts from an intermediate-level to an advanced-level project. If your skills are not up to it, it might be best to call in a professional for the electrical work, the vent work, or both.

Another possible complication is if substantial cabinetry work is needed, such as installing an upper cabinet to mount the oven and run the ductwork and the electrical cord. Again, this turns an intermediate project into a more advanced one, and it can turn a few hours of work into a weekend project.