The microwave is a kitchen staple and out of all the appliances in your kitchen you might think your microwave is the easiest to replace. Well unless you’re replacing a countertop microwave – this couldn’t be further from the truth. Built-In, Over the Range and Drawer Microwaves can be some of the most difficult appliances to change in your kitchen and if you’re not careful, the smallest major appliance in your kitchen, could easily become the most expensive to replace.
5 Types of Microwaves
Traditional Side Swing
For the purpose of this report, we will be reviewing what you need to know when replacing the built-in types.
There are three key things you need to consider before replacing your built-in microwave:
- Ventilation Type
- Electrical Capacity
The first consideration when replacing a microwave is size. And the key to a successful microwave install is ensuring you’ve chosen a model size that will fit into your cabinet.
Across all brands, common microwave sizes are 24”, 27” and 30” units. These sizes refer to the width across the microwave from left to right. But they aren’t exact, often varying by a few 8ths of an inch or more. So it’s not as easy as replacing a 30” microwave with another 30” microwave. Even if it’s the same brand, the sizes can vary as modern microwaves are typically bigger than models from 5-10 years ago.
The most important measurement is the height and width of your existing microwave.
For traditional side swing microwaves, this will include the trim kit – which is the frame surrounding your microwave. A trim kit ensures your microwave fits snuggly into place, hides any gaps around the unit and can make up the visual difference in width when installing it directly above an oven that’s wider. You’ll want to measure the height and width – left to right – of your trim kit, as well as the cabinet it’s sitting in.
The reason for this is to make sure your new microwave & trim kit will fit properly within the amount of horizontal or vertical space you have in your cabinet. For example, if your current trim kit comes right up to the top of your cabinet and the new trim kit is even 3/4” of an inch taller, you won’t be able to open the cabinet doors above. Same thing for the sides – if there isn’t enough clearance space between the trim kit and the cabinet next to it, the cabinet may not be able to open properly. Conversely, if the new trim kit is smaller than your existing one, it could leave the rough edge of the previous cutout exposed.
The difference with drawer, drop-door and over-the-range microwaves is they don’t require trim kits, so you’ll be measuring the microwave unit itself. And because these units don’t have trim kits, there is even less wiggle room when it comes to size. If your new microwave is smaller than the old model, you’ll have to consider either adding filler pieces or a complete cabinet replacement.
If you’re hoping to replace your microwave with one of a different configuration – for example going from a traditional side swing microwave to a drop down door or drawer microwave, keep in mind the dimensions for the these unit types are significantly different and you will almost certainly need to replace your cabinet.
Over-the-range microwaves are a great way to save on space because they combine a vent hood and microwave into one. However, OTR microwaves are only made in 30” and 36” widths and therefore can only accommodate ranges and cooktops up to 36” wide. For ventilation to be effective, it needs to cover the surface area below, otherwise odors and vapors will escape on the sides. And from an aesthetic stand point, it looks best to have your OTR match the width of your range or cooktop below.
For any microwave style, you’ll also want to know how deep your cabinet is. Shallow cabinets – or those less than 24” deep will require a space-saver unit so the microwave doesn’t stick out further than it should. And, if the outlet is located directly behind the microwave, it will push the microwave away from the wall approximately 2-3 inches.
If you’re purchasing an over-the-range microwave, keep in mind that modern units are greater in capacity and typically 15 1/2” deep so they stick out an additional 3-4” versus older models. However, if your cabinet is greater than 15 1/2” you’ll need to purchase a OTR unit with an inset door hinge to ensure it will open properly.
Over-the-range microwaves come in two installation types – vented and recirculating. The easiest way to see if your old microwave vents is to open the cabinets above the microwave. If you see a ventilation tube taking up most of the space in that cabinet, then you have a vented microwave and your next microwave should be vented. You could replace a vented microwave with a non-vented or recirculating model – but it will require additional installation costs to close up the vent connection to the outside and leaves a big hole in your upper cabinet.
Recirculating microwaves are generally found in apartments and condos. Instead of venting dirty air to the outside, they pull in the air through a series of filters and push it back out through the top grille. If you have a recirculating unit, you should see an air filter or grille on the bottom side of the microwave.
The standard electrical current in homes in the US is in a range of 110 to 120V. Some circuits used for large appliances such as dryers, cooktops and ovens use a voltage in the range from 220 to 240V.
Microwaves can vary in voltage and amperage requirements, depending on the technology it uses. The average microwave calls for 120 volts and 15 amps. However microwaves with speedcook technology can require up to 240 volts. If your current outlet is wired for 120 volts, a 240 volt microwave will not operate properly in that plug. You will receive a fraction of the cooking power you should and you run the risk of blowing a fuse. If you’re not sure how much voltage your outlet has, you can use a multimeter to find out.
Microwaves with higher wattage or convection technology will require 18-20 amps rather than the traditional 15. A 20amp plug socket looks different than a 15, so it will be easy to tell the difference if you can get back there to see it. Or you could just check the microwave’s owner manual.
If your new microwave requires a different voltage or amperage than what is currently wired in your home, you’ll need to contact an electrician to adjust the circuits.
If you’re completely changing microwave configurations or moving the location of your microwave and aren’t sure what modifications will be needed, ask your appliance store for a survey. Surveys typically incur a small fee but having a certified installer assess the situation greatly reduces the chances you’ll run into costly problems when it’s time to install your new microwave.