This is a complete guide to installing an over-the-range microwave oven. Whether you’ve just bought a microwave oven, are redesigning your kitchen, or are still deciding which microwave is right for you, this guide provides helpful step-by-step installation instructions for each.
I’ve broken down everything you’ll need to complete the installation. Some of you will need tools that others don’t, depending on your workspace. To ensure faster and safer installation, I recommend getting a friend to help. Over-the-range microwaves are pretty cumbersome (see the retrofitted ovens here), and you’ll appreciate having some assistance. Before you get started, check the list below for the tools needed for the job.
Tools You Will Need
Before getting started, you’ll need to gather up the following tools:
- Saw to cut exhaust opening (if needed)
- Metal hole cutter (for metal cabinetry)
- 1 ½” wood bit (for wood cabinetry)
- Drill bits (½”, 5/8″, and 3/32″)
- Protective drop cloth
- Phillips screwdriver
- Protective eyewear
- Measuring tape
- Scissors
- Pencil
- Tape
- Drill
You probably have a specific place in mind for your microwave (e.g., over your stove). Before starting the installation, I advise that you make sure that the wall construction, counter, cabinetry, and kitchen space all meet the requirements for installation.
Installing an Over-the-Range Microwave Oven
Now that you’ve determined that your workspace can accommodate and support an over-the-range microwave oven (see this review for the best under $200 microwave ovens), it’s time to prepare the area. Preparing the area is very important, as it is the foundation of your microwave (for the top picks under $150 click here). This includes preparing the wall, installing the hood duct, and connecting the electricity.
1. Locating Studs
The first thing you need to do is to determine the position of the stud on the wall. I recommend using a stud finder device. Alternatively, you can simply tap the wall surface with a hammer to accomplish this. You’ll know that you’ve located the stud when the sound is solid rather than hollow.
The device should be attached to a wall stud measuring at least 2 x 4 inches. Next, find the center of the stud. This can be done by probing the wall with small nails to identify the edge of the stud. Do this after using the stud finder. I like to place a pencil mark in the middle between the edges to identify the center.
2. Proper Grounding
Before handling any electrical tasks, make sure that your equipment is grounded. In an electrical short circuit, grounding reduces the risk of electric shock by providing an escape line for the current. You must confirm this before proceeding.
Your over-the-range microwave should be plugged into a wall outlet that is properly installed, grounded, and complies with national and local regulations.
Furthermore, your microwave is equipped with a 3-pin grounding plug. Under no circumstances should you cut or remove the grounding pin from the plug.
Connect the power cord to a separate 120 volt AC, 60 Hz, 15 amp or more branch circuit, single-ground outlet. It should be located directly above the installation location in the cabinet.
3. Ventilation
Does your hood lead to the outside? If this is the case, a hood exhaust duct is required. All ductwork systems should be metal; never use plastic. To begin this process, I first confirm that all connections are securely in place.
If possible, it is best to use straight ductwork. The use of elbows, adapters, walls, and roof caps will only serve to cause more airflow resistance. If you cannot have a straight duct, you will need to calculate the total length, plus the equivalent lengths of all transitions and adapters and the length of all straight ductwork sections.
Doing so will allow you to calculate the airflow resistance. The total length should be less than 140 feet.
4. Unpack Your Microwave
Thoroughly inspect the device to make sure it is free of dents, scratches, or cracks. Open the microwave to ensure that the door isn’t bent, the door seal isn’t damaged, and the door hinge is in good working order.
If not, contact the dealer where you purchased the over-the-range microwave. You don’t want to install a previously damaged microwave. This can cause a number of problems, from inoperability to damage to surrounding surfaces.
If the appliance you purchased has a mounting plate, place the microwave oven on its side. Remove the mounting plate by taking out the screws that secure it to the back of the microwave. You can pitch these screws, as you won’t need them.
5. Connecting Your Microwave and Ventilation
Your microwave can be connected to three different types of hood ventilation systems: Horizontal exhaust (external ventilation), recirculating (non-ventilated and ductless), and vertical exhaust air (external ventilation).
Horizontal Exhaust
If you have a horizontal exhaust, it means you are using outdoor ventilation. First, remove the screw(s) on the fan cover bracket and set them aside for later use. Next, take off the cover bracket and gently lift up on the hood unit.
Take the wire out of the cavity carefully, as pulling on any wiring can damage them. Rotate the exhaust fan assembly 180 degrees so that the hole on the blade faces the back of the microwave oven. You need to lift the power cord from the exhaust and put it in the over-the-range microwave.
Replace the exhaust with the microwave. Be careful not to pinch the cable as you reinsert it into the cavity. Replace the fan cover bracket. You need to make sure that the blades are visible through the rear opening of the microwave oven before proceeding any further.
Attach the fan cover bracket to the over-the-range microwave with the screw(s) you removed a moment ago. In order to work in a horizontal position, the hood must not be rotated.
Insert the baffle assembly into the slot and connect it to the back of the mounting plate. Then, screw it in place.
Recirculating Air
If you have a recirculation system, it means it is unventilated and ductless. These devices are usually pre-assembled for recycling and do not require further installation. Refer to the user manual for maintenance, filter maintenance, and other essential information.
Vertical Exhaust
If you have a vertical system, this means you are using external ventilation. Start by removing the screws from the fan cover bracket and set them aside. Remove the bracket from the fan cover. Carefully pull the fan unit out of the hood and pull the cable out of the cavity.
Once again, take care not to pull on any wires, as doing so could damage them. Rotate the fan assembly 90 degrees so that the hole on the fan blade faces the top of the oven. Be careful not to pinch the leads between the inner bracket and the fan assembly.
Put the lead cable in the cable box and use the screws you removed at the start to install the fan cover bracket to the device for vertical exhaust. Slide the damper assembly into the slot and secure it to the fan cover. Use screws for fastening.
6. Installing the Mounting Scale Plate
To start, use wood screws to fix the mounting plate to the stud. Then, use the toggle bolts to connect the mounting base through the holes and install the toggle nuts.
It is best to connect the mounting base to the wall with toggle bolts. Close the lever nut and insert it and the bolt into the hole in the wall. Use wood screws to secure the mounting plate to the stud.
Carefully align the plate and secure it in place by tightening the bolts. Pull the toggle bolt toward you, and then turn it clockwise to tighten it.
In this last step, it is recommended that two people place the microwave on the mounting base. Gently place the microwave on the stove. It is advised that you place a piece of cardboard or a protective cloth or towel between the two pieces to avoid scratches and damage.
Push the unit back to the end. Align the bottom rear edge of the microwave oven with the mounting plate, and then pass the power cable through the hole at the bottom of the cabinet. Hang the microwave on the lower edge of the mounting base, and then turn it over.
When lifting the microwave, make sure that the power cord extends to the edge of the opening. In wall-mounted installations, the cable opening may need to be enlarged. Tighten the two-part fastening screws in the grease filter hole. Next, you need to install the grease filter by putting it in the hole. Slide back and push it into place.
Use the supplied screws and washers to install the device on the wall mount. Bundle the power cable and put it inside the cabinet. Remove all packaging materials from the microwave and plug in the power cord. You are now ready to use your newly installed over-the-range microwave oven.
Is It Hard to Install an Over-the-Range Microwave Oven?
It isn’t necessarily hard, but it certainly helps to have an extra set of hands to assist you. Over-the-range microwave ovens are big, bulky, and woefully unbalanced. As such, it can be a real pain trying to juggle the appliance during installation.
How High Should a Microwave Be above the Stove?
The common rule of thumb is 30 inches. Most manufacturers state that the top of the microwave or bottom of the cabinet needs to be 30 inches off the stovetop (see ‘How Many Inches Does a Microwave Have to Be Above a Stove?‘ post). Your average over-the-range microwave is around 16 inches in height; give or take an inch or two.