How to Install an Over The Range Microwave

Preparing for Installation

Turn off the power. Since a microwave is an electrical appliance, you will need to take care to avoid electrocution or other damage. Before you start installation, go to your circuit breaker, and flip the breaker for the range to the “off” position.

Make sure there’s an outlet nearby. Most over the range microwaves include a short power cord that is designed to feed upwards into the cabinet that the appliance will sit underneath. Ideally, there will be an electrical outlet inside this cabinet that you can plug the power cord into. Your microwave’s installation instructions will specify whether there are acceptable alternative locations for the electrical outlet. If there is not an outlet in a convenient location, contact an electrician for assistance installing one before you put the microwave in place.

Check to make sure your microwave can be installed at the proper height. In general the bottom of the microwave should be no higher than 54 inches (140 cm) from the floor. In addition, there should be approximately 20 inches (51 cm) to 24 inches (61 cm) between the bottom of the microwave and the top of the range. This will allow you to use both the microwave and the range safely and comfortably. Use a tape measure to verify the height of your microwave. Measure from the bottom of the cabinet you will install the microwave below to the height of the microwave. Make a mark at this spot. Measure the distance between this mark and the floor, and the top of your range, to make sure that the microwave will be situated within the acceptable height range.

Determine the ventilation direction. The microwave itself will have a fan, and since it sits above the range (where a range hood would normally go), both appliances will have to ventilate outside together. Ordinarily, there are two options: either the appliances will ventilate horizontally through a tube in the wall, or vertically, first through the cabinet above the microwave and then the ceiling or higher up on the wall. Your microwave may have additional fittings which you should set in place in order to allow it to ventilate properly. Check the installation instructions that come with your particular model to be sure. If you do not already have a ventilation system in place, contact a contractor to have one installed.

Reframe the opening, if necessary. If your kitchen cabinetry and framing are sturdy, they may be sufficient to support a relatively heavy over the range microwave. If the materials are less robust, reframe the area where you will install the microwave with two by fours. Some experts recommend reframing in all cases. Your microwave should come with a kit that has a framing template. Place it where you want the microwave to sit, and follow the guidelines to cut through the drywall. Remove the drywall and pull out the insulation from the area inside the wall. Secure two by fours between the wall studs. Check the instructions provided with your microwave for the exact dimensions. Fill in any empty space with new insulation.

Arranging the Setting

See if your microwave has an installation template or wall plate. Your model should come with a template to help guide you when installing mounting hardware. Place this on the wall, and the template should tell you where to place the hardware. Some models also come with a mounting bracket that will have pre-drilled holes so you can easily screw it in place. Use a level to make sure that the template is square and that the microwave will sit properly in place.

Find at least one stud. If you didn’t reframe the installation site, you’ll need to attach the mounting hardware to at least one stud in the wall. Use an electronic stud finder, or gently tap on the wall with a hammer. When the taps sound dull instead of hollow, you have located a stud. Mark the site on the wall. Studs are usually 16 inches (41 cm) inches apart on the wall. Once you find one, measure 16 inches to the either side to mark others. Using your template, make sure that the hardware will be mounted on at least one of the studs. If not, reframe the site or contact a contractor for help.

Drill holes in the template or attach the wall plate. Usually, over the range microwaves will be installed using toggle bolts. Predrilling holes for these bolts will make installation easier--just follow the guidelines on your template. If you are using a wall plate, go ahead and install that using the hardware and guidelines given in your model’s instructions. Most likely, you will need a couple of drill bits: smaller ones for the toggle bolts, and a larger one to make a hole to feed the microwave’s power cord through the cabinet above the appliance (if there isn’t already one). Check your model’s instructions, and always use the recommended tools.

Set the microwave into position or onto the wall plate. It will help to have another person to help you hold up the microwave. Push it up and bring it up to the bottom of the cabinet. If your model has a wall plate, fit it into the bracket that will help hold it in place. Make sure that someone keeps holding the microwave in place for now.

Plug in the microwave. Feed the microwave’s power cord through the hole drilled in the bottom of the cabinet above the appliance. Plug the cord into the outlet within the cabinet, but don’t turn the power back on yet.

Thread bolts through the bottom of the cabinet. Feed the bolts (or screws) supplied with your microwave (or recommended by its instructions) into the holes you previously drilled in the bottom of the cabinet. They should slip into slots in the top of the microwave. Tighten them using a wrench (or screwdriver) until the microwave is securely held in place. Carefully let go of the microwave at this point to make sure that it stays in place.

Connect the blower. Slide the exhaust fan supplied with your microwave into place at the ventilation site. Specifications will vary from model to model, so read the instructions provided with yours. Most manufacturers also recommend using an approved sealant around the edges of the fan’s housing to make the connection impervious. You may need to take the fan out and change its direction, depending on the orientation of your ventilation system.

Test the microwave. At this point, you can finally flip the circuit for the range back to the “on” position. Verify that your microwave is getting power, and test it by heating something to make sure that the appliance is working properly. If your appliance does not seem to work properly, read the troubleshooting section of the manual, if it has one, or contact the manufacturer.