Built-In Microwave: A Handy How-To Guide

Installing a built-in microwave is a satisfying do-it-yourself project that can upgrade your kitchen’s functionality and appearance. With the right planning and preparation, you can safely and successfully install a built-in microwave on your own.

This comprehensive DIY guide provides tips on every step, from measuring your space to testing the installation, to help you install your microwave with confidence.

Step 1: Choose an Appropriate Microwave Model

Choosing the right microwave model for your needs and installation location is crucial for a smooth DIY installation.

Consider the following when selecting a built-in microwave:

• Installation type – Choose a microwave specifically made for built-in installation. These include trim kits and have ventilation systems that work for confined spaces.
• Dimensions – Carefully measure your available space for the microwave to ensure an accurate fit. Leave some wiggle room.
• Electrical requirements – Select a microwave with voltage, amps, and Hertz that are compatible with your kitchen’s electrical system. This info should be printed on the back of the unit.
• Ventilation – Microwaves require proper ventilation. Ensure the CFM rating meets minimum kitchen ventilation CFM requirements.
• Features – Decide which microwave features suit your needs before purchasing, like smart features, sensor cooking, integrated racks, etc.
• Budget – Built-in microwaves span a wide range of prices. Set a budget and stick to microwaves in your affordable range.

Step 2: Prepare the Installation Space

Preparing your workspace is one of the most important first steps to safely and effectively install your built-in microwave.

• Turn off power supply – Turn off the kitchen’s electricity to the installation area at the circuit breaker to prevent electric shock.
• Clear the area – Remove any existing microwave or range hood. Also clear at least 30” of counter space in front of the installation area to maneuver the new microwave.
• Clean space – Use a vacuum and all-purpose cleaner to thoroughly clean the area to ensure proper ventilation.
• Perform initial measurements – Confirm the exact height, width, and depth of your space to verify accurate microwave fit.

Double check your preparations with the following checklist:

•  Electricity turned off at circuit breaker
•  Existing microwave/range hood removed
•  30” of counter space cleared
•  Installation area thoroughly vacuumed and cleaned
•  Exact measurements of space confirmed

Step 3: Install the Mounting Plate

The mounting plate securely holds your built-in microwave in place. It must be professionally installed into the wall or your cabinetry depending on your installation location.

Wall Installation

For best results, use these tips when installing the mounting plate into drywall:

• Place mounting plate directly into wall studs whenever possible for the most secure hold. Use a stud finder to locate studs.
• If a stud cannot be used, use hollow wall anchors rated to hold the weight of your microwave.
• Check the manual template for your microwave’s specific mounting plate measurement instructions. These indicate Exact locations to drill holes to align with holes on the back of the microwave.
• Drill holes for screws slightly wider than the screws (usually less than 1/8 inches wider) to give some leeway.
• Make sure mounting plate is level using a spirit level tool. Adjust plate until perfectly level.

Cabinet Installation

Follow these best practices when installing the mounting plate inside cabinetry:

• Fully open cabinet doors to allow room for drilling andscrewdriving.
• Remove any shelving that interferes with installation area.
• Use a right angle drill for easier installation inside the cabinet.
• Pre-drill screw holes in the cabinet walls to prevent cracking wood.
• Make sure mounting plate sits flush against cabinet back wall without gaps.

No matter where you install, carefully follow the instructions packed with your microwave kit to properly install the mounting plate.

Step 4: Prepare Electrical System

Microwaves have specific electrical requirements that your kitchen wiring system must match. Prepare your kitchen’s electrical system by following safety precautions and Michel installation best practices.

Safety Precautions

• Never connect a microwave directly to household wiring – this is extremely dangerous. Always use a UL-listed power supply cord kit recommended by the manufacturer.
• Do NOT install a ground wire to gas pipes, plastic pipes or the neutral circuit wire. This can cause electric shock.

Installation Tips

• Leave an extra 3 feet of slack in the power cord inside the cabinet to have room to pull microwave out for repairs if ever needed.
• Keep the power cord away from any heating elements like the range cooktop burner.
• Position outlet box at least 3 inches from the floor (or per local building codes) for safety and accessibility.
• Group appliance outlet boxes together whenever possible for a streamlined appearance.

Follow all included manufacturer electrical instructions carefully and precisely.

Step 5: Install the Microwave

You’re now ready to safely lift the microwave and secure it carefully into place.

Lifting Precautions

Microwaves can be bulky, heavy, and awkward to lift. Follow these safe lifting methods:

• Always lift the microwave with two people – do not attempt to lift alone.
• Face the microwave instead of twisting, always lifting with your legs not your back.
• Ensure you both have a tight grip before lifting using the handle indentations.
• Move slowly and carefully.

Mounting Tips

When mounting the microwave:

• Allow the power cord to hang loose and untwist freely while lifting unit. Don’t trap or tug cord.
• Align microwave vent holes precisely with mounting plate holes.
• Hang microwave on top ledge of mounting plate first, then swing bottom in and up.
• Insert mounting screws through microwave back holes into mounting plate pre-drilled holes. Tighten screws securely.
• Do not pinch cords between unit and wall. Leave slack.

Step 6: Install Venting System

A key component of a safe and properly functioning built-in microwave is proper ventilation. An exterior venting system is required for built-in models.

Ventilation Guidelines

Improper venting causes microwave fires and dangerous fume leakage. To safely vent:

• Run ductwork from the top or rear exhaust opening, depending on model. Never from bottom.
• Vent exhaust to building exterior, not into gaps inside cabinet space or ceiling.
• Use rigid or semi-rigid metal ductwork for best airflow (flexible plastic can trap humidity and condensation).
• Calculate required duct measurements:
  • For less than 5 ft duct – 3 1/4” x 16” rectangular or 6” diameter round
  • For 5-14 ft duct – 3 1/4” x 20” rectangular or 7” diameter round
• For straight horizontal runs under 40 ft, allow 2 ft rise per foot of duct length.

Improper venting voids warranties. Follow exact ventilation requirements for your model in manual.

Step 7: Install Trim-Kit (Optional)

Trim kits neatly finish off the built-in installation with attractive built-in appearance. Purchase microwave trim kits separately.

Trim kit contents vary but often include:

• Decorative vent grille
• Side panels, bottom panel or glass display door
• Mounting hardware
• Installation template

Trim kits snap into place on tabs or slots on microwave. Carefully follow the template guide included with kit and the instructions in your owner’s manual.

Key steps usually include:

1. Attach side and top pieces to microwave.
2. Fasten bottom panel pieces.
3. Secure variable width trim strips on each side.
4. Fix decorative outer trim using attachment clips or screws to finish off edges around unit.

Step 8: Perform Final Safety Checks

Always confirm 100% safe functionality before regular operation after completing DIY electrical installations.

• Confirm microwave is level after final mounting.
• Ensure trim kit pieces are securely fastened, not loosely hanging.
• Check venting system for air leaks that allow heat or fumes to escape.
• Inspect to confirm cords do not have any snags or traps behind microwave or in cabinet interior.
• Ensure child lock-out is enabled if you have kids.
• Re-read safety precautions in manual and on labels before use.

Then test simple functions:

• Start microwave without food inside and listen closely for odd buzzing or rattling noises, stopping immediately if heard.
• Heat a microwave-safe container filled at least halfway with water on high for 1 minute. Unit should run quietly. Water should be piping hot.
• Set the clock and kitchen timer features and confirm buttons work properly to start and stop countdown.

Troubleshooting Common Issues

Despite the best planning, you may encounter issues along the way. Tap into the wisdom below to troubleshoot the most common DIY built-in microwave installation problems.

Microwave Does Not Turn On

First, confirm the electrical outlet functions properly by plugging in a small appliance and testing operation. If other appliances turn on, the issues may be:

• Faulty power cord – carefully inspect cord for damage. Test voltage with a voltmeter. Replace cord if needed.
• Loose internal wiring connection – call for service from certified technician.
• Tripped circuit breaker – carefully reset breaker switches fully to “On” positions.

Microwave Will Not Close Properly

If the microwave shifts, sags, or cabinet door won’t close, the unit likely isn’t properly secured by the mounting plate screws.

• Loosen mounting plate screws and lift and adjust microwave to realign.
• Check rear alignment on interior cabinet wall and confirm plate is centred & level.
• Apply downward pressure while retightening screws through microwave back.

Still won’t close properly? Cabinet alignment bars may resolve:

• Place leveled mounting bars across rear cabinet walls.
• Rest unit on bars while retightening screws to improve weight distribution.

Loud or High-Pitched Noises

Loud buzzing, high-pitched whistling or chirping sounds usually indicate a airflow issues.

• Check that venting ductwork is not kinked or blocked.
• Remove any debris or product packaging blocking vent.
• Open cabinet doors fully to allow more room for ventilation.
• Ensure recommended ductwork measurements were followed.

Seek professional installation help if issues persist despite troubleshooting.

Maintaining Your Investment

Caring properly for your built-in microwave ensures longevity.

• Frequently degrease the vent filters and ductwork to improve airflow.
• Use microwave-safe cookware to prevent interior damage.
• Clean the interior regularly with a hot, damp cloth – no harsh cleaners.
• For stubborn messes, boil a microwave-safe cup of water inside unit for easy steaming.
• Check components for signs of wear and failure and replace parts as needed.
• Hire certified technicians for complex repairs.

With diligent care and maintenance, your DIY installed built-in microwave can provide reliable performance for years of cooking convenience.

Enjoy Your Custom Built-In Microwave!

Congratulations on your newly installed built-in microwave! As you gleefully reheat leftovers and pop endless bags of popcorn in your kitchen’s custom focal point, savor the pride and satisfaction achieved by elevating your home with your own hands.