An over-the-range microwave (also called OTR microwave) combines a microwave with a range hood ventilation function in a single unit mounted above the stove. The install replaces an existing range hood or microwave; the dimensions are standardized so the swap is straightforward. Two-person work because of the unit's weight.

This guide covers a standard OTR microwave install. Built-in microwaves in cabinets and countertop microwaves are different installations.

Before you start

Three things to settle:

1. Mounting bracket and wall plate. OTR microwaves install with a wall mounting plate (anchors to studs) and an upper bracket (anchors to the cabinet above). Both must be securely mounted before the microwave can hang. The plate provides shear support; the cabinet anchor prevents the microwave from tipping forward.

2. Vent direction. OTR microwaves can vent three ways: outside (preferred — connects to existing range hood duct), upward (into a cabinet above with a duct), or recirculating (filter and return to kitchen). Verify the new microwave's vent matches your existing setup.

3. Power outlet location. OTR microwaves plug into an outlet typically located inside the cabinet above (in the soffit/bumper). The outlet should be a dedicated 15A or 20A circuit. Verify before installing.

What you'll need

Tools

Cordless drill
Phillips screwdriver
Stud finder
Tape measure and level
Pencil
2 helpers (microwave is heavy and awkward)

Materials

Over-the-range microwave (matching size to space)
Mounting kit (typically included)
Toggle bolts or wood screws (for non-stud anchoring if mounting plate doesn't align with studs)

OTR microwaves are 60-80 lbs

These units are heavy. Lifting one above your head while connecting wiring and securing mounts is a two-person job, ideally three (one to lift, one to anchor screws, one to handle wires).

Don't try to install one alone. Drops cause injury and damage. Borrow help from a neighbour or friend for the 30 minutes of mounting.

Step-by-step instructions

Remove the existing range hood or microwave

Turn off the breaker. Disconnect the existing unit from electrical and ductwork.

Unscrew the existing mounting hardware. Lower the unit out — typically requires two people.

Verify the rough opening dimensions

Standard OTR microwave dimensions: 30 inches wide × 16-17 inches deep × 16-18 inches tall.

Confirm cabinet opening width is 30 inches (most ranges are 30 inches wide). Confirm cabinet bottom-to-counter clearance is at least 13 inches (some cookers/ranges need more clearance).

Install the wall mounting plate

Locate studs in the wall behind the microwave's planned position.

Hold the wall plate against the wall at the height specified by the microwave's instructions (typically a specific dimension above the range top).

Drive included screws through the plate into studs. If studs don't align, use toggle bolts (rated for the microwave's weight) at non-stud locations.

Verify the plate is level.

Drill the bracket holes in the cabinet above

The microwave hangs partly from the wall plate, partly from anchor screws into the cabinet above.

Use the included template or measurements to mark drill points on the cabinet floor (the underside of the cabinet that will anchor the microwave from above).

Drill pilot holes.

Route the power cord and any duct

Most OTR microwaves have a power cord that exits through the top of the unit and plugs into an outlet inside the cabinet above. Plan cord routing.

If venting outside, connect the duct adapter at the top of the microwave (or back, depending on direction). Configure the microwave's vent direction per its instructions — there's usually a small panel or fan blade orientation that determines vent direction.

Lift and hang the microwave

With your helpers, lift the microwave up to the install position. Hang the unit's keyhole slots over the wall plate's hooks.

The microwave hangs from the wall plate — your helpers can release.

Plug the power cord into the outlet inside the cabinet above.

Drive cabinet anchor screws

From inside the cabinet above (open the cabinet doors), drive the anchor screws down through the cabinet floor into the microwave's top.

Tighten firmly. The microwave is now anchored from both wall and cabinet.

Connect duct (if venting outside)

Inside the cabinet above, connect the existing range-hood ductwork to the microwave's vent. Use foil tape to seal the joint.

If the microwave vents up into the cabinet (no exterior duct), no connection needed — the cabinet has an opening to release air, OR the air is recirculated in the kitchen.

Test power, fan, and microwave function

Switch the breaker back on. Test the microwave: power on, set time, run for 30 seconds — should heat normally.

Test the fan: low and high speeds. Verify air movement.

Test the lights underneath (over the range): work and dim if applicable.

Common mistakes that cost you

Inadequate wall plate anchoring. Microwave can pull free. Always anchor wall plate into at least 2 studs OR use rated toggle bolts.
Wrong vent configuration. Microwave vents 3 ways (outside, up, recirculating). Set the correct direction per instructions before mounting.
Working alone. Microwaves are 60-80 lbs and awkward to lift overhead. Always use helpers.
Not testing before walking away. Defective units sometimes ship — test all functions before considering install complete.
Wrong cabinet clearance. Most OTR microwaves need 13+ inches between range top and cabinet underside. Verify before buying.

Frequently asked questions

Can I install one alone?

Strongly recommended against — these are heavy and awkward at install height. Two people minimum, three is easier.

If you must install alone, use a temporary support (boards braced from the range top to support the microwave during connections).

Can OTR microwaves be installed without venting outside?

Yes — they can be configured to vent up into the cabinet (with an opening) or to recirculate (filter and return to kitchen).

Recirculating is least effective; outside venting is best. Match the configuration to your existing setup or your venting capability.

When to call us instead

If you don't have an existing OTR or range hood, installing one new requires running ductwork and possibly electrical. We do this as part of kitchen renovations.

Book a free 60-minute site visit →

Related Ottawa services

If you're updating kitchen appliances comprehensively, our kitchen renovation team handles appliance installation as part of fixed-price scopes. Book a free 60-minute consultation.