How to Install an Induction Cooktop
by Michael Chotiner
Induction cooktops, which heat pots and pans with magnetic fields instead of flames or heating coils, have been available since the 1950s, but they are only just now catching on among home remodelers who aspire to state-of-the-art kitchens. Induction cooktops offer significant advantages over both gas and electric models because they:
- Cook foods faster
- Are more energy-efficient
- Allow more precise temperature control
- Are easier to keep clean
- Are safer
True, the cooks in your family will need to change some long-held cooking habits in learning to prepare foods with an induction cooker. You may even need to replace your favorite cookware with cast iron or magnetic, stainless steel pots and pans. But installing an induction cooktop is no more difficult than dropping an electric cooktop into a counter and connecting the wiring.
Induction Cooktop Choices
There are many potential things to consider when selecting an induction cooktop, including:
- Number, sizes and wattages of cooking elements
- Configuration—some models offer a combination of induction and standard electric coil elements
- Color of the cooktop surface (black or stainless steel; trim or no trim)
- Special features, such as the ability to link elements so you can use oversized rectangular griddles
But, for the purpose of planning an installation, it's really only the key dimensions of the cooktop that matter. These include:
- Overall or nominal size
- Cutout size
- Depth of unit below the counter
Illustration courtesy of GE Appliances
Mainstream models with four or five cooking elements tend to come in only two nominal sizes: 30 in. and 36 in. Your choice here could be based on:
- If you're aiming to replace an existing cooktop and want to minimize the time and effort of adjusting the countertop cutout, choose an induction cooktop of the same make and nominal size. Some models (notably GE Profile CleanDesign PHP 900) offer trim kits that nicely cover gaps when the existing cutout is oversized for the new cooktop selected.
- If you're installing an induction cooktop for the first time in a previously uncut countertop, match the nominal size of the unit to the size of the base cabinet into which it will nest. A 30-in. cooktop should fit into a 30-in. (or wider) cabinet; a 36-in. cooktop should fit into a 36-in. wide (or wider) cabinet.
In addition to the two most common sizes, induction cooktops are also available in smaller and odder sizes. European makers offer cooktops that are nominally 23, 31 and 37 inches wide, and you can also find 12-, 15- and 24-in. induction cooktops on the market. Whichever you choose, make sure to check the cutout size and overall depth below the cooking surface before making a final selection. Only some induction cooktops are recommended for installation above a wall oven set into a base cabinet—so if that's your ultimate plan, make sure to choose a cooktop and oven that are compatible.
Observe Minimum Clearances
When you're planning an induction cooktop installation, make sure that the installed unit will have adequate clearance from combustible materials above and below, and on either side. Each manufacturer has its own recommendations, but the illustrations below, taken from installation instructions for a GE Profile induction cooktop, show the key clearances that should be considered.
Illustration courtesy of GE Appliances
Induction cooktops require a dedicated, grounded 240-volt circuit protected with 40- or 50-amp breakers that terminates in an approved junction box mounted below the counter on the cabinet back or on the wall behind it. Manufacturers' recommendations for the optimal location of the junction box can vary based on whether the power supply cable feeds into the cooktop's housing from the left or right, but it should be about 16 in. below the underside of the countertop so the connections inside the box won't be exposed to excessive heat.
- If you're simply swapping out an old electric cooktop for a new induction unit of similar size and power, the existing circuit and receptacle will probably work without modifications, but double-check the manufacturer's specs for total amperage to make sure the existing circuit breaker has the adequate rating. Consult a licensed electrician if you're not sure.
- If you're installing an induction cooktop in a new location, have a professional electrician determine whether your home's existing electric service can support the appliance and do the necessary wiring.
Most manufacturers supply a length of flexible armored cable to connect the cooktop to the home wiring at the junction box, but this isn't something I would do myself without input from a licensed pro. There are too many potential variables in existing wiring and local codes to provide comprehensive instructions here, for example:
- Is the power supply 3- or 4-wire?
- Is a ground wire present?
- Does your local code permit grounding through neutral?
- Is aluminum wiring present and if yes, do you have the right wire nuts to make the connections?
I'm lucky to have a professional electrician for a good friend, and I invite him over for barbecue when I need to hook up a new appliance. If your barbecue isn't as good as mine, you may need to hire a licensed pro.
Preparing the Countertop Cutout
In the easiest case, you're replacing an existing cooktop with an induction unit of the same nominal size, and the existing cutout is about the right size. If you're really smart (or lazy), you chose a model from the same maker as the old cooktop who supplies trim kits and fillers to conceal any gaps, should the existing cutout prove to be slightly oversized.
If an existing cutout is too small, or if you're installing the induction cooktop in a new countertop, you're going to have to cut. Should you do it yourself?
- If you need to slightly enlarge a cutout in a stone top, you can do it with an angle grinder and a silicon-carbide or diamond wheel, but it'll be messy. Figure out how to control the dust and water beforehand. Don't try to make a whole new cutout in stone yourself; it's too risky.
- If the existing top is solid surfacing, you might be able to do it yourself—if you have a powerful plunge router and a 3/8-in diameter single-flute bit with ½-in shank. Be sure to leave the corners of the cutout rounded; don't use a jigsaw.
- If the existing top is plastic laminate, go for it if you've got a drill with a ½-in. bit, a portable circular saw with a 40-tooth carbide blade and a jigsaw.
Installing the CooktopOnce you've prepared the cutout according to the manufacturer's specs, you're done with the hard part. Various models from different manufacturers require different fastening systems. It's important to follow the manufacturer's instructions to the letter. It's also a good idea to line the countertop edges around the cutout with reflective aluminum tape to block heat build-up and prevent damage to the countertop.
Whirlpool induction cooktops, for example, use proprietary brackets (supplied with the cooktop) that are fastened to the left and right sides of the cutout, as shown in the illustration below. Then the cooktop is dropped into the prepared opening where it snaps in place with clips.
Whirlpool Bracket System
GE induction cooktops are dropped into the prepared cutout and held in place with clamps that are fastened to the bottom housing with screws. You must be careful not to over-tighten the clamp when setting the cooktop into a stone or solid-surface top.
GE Appliances Hold-down Clamp System
Once the cooktop has been fastened securely in place, call your licensed professional electrician to wire connect the power line from the cooktop to the circuit at the junction box. Make sure that power to the circuit has been turned off at the panel before he starts making the hookup.
Now enjoy your new induction cooktop!
About the author: Michael Chotiner is an expert on DIY appliance installation, and writes tips for homeowners for Home Depot. Michael's advice for induction cooktops is based on his many years of experience as a carpenter and general contractor. To view Home Depot's extensive selection of induction cooktops, click here.