Replacing an old, coil-type kitchen electric cook top with one of the sleek new glass-top models might be more of a challenge than the weekend do-it-yourself project it may seem to be at first. In addition to the hundreds of dollars you typically spend for a modern cook top, you might have to pay an electrician to do some rewiring and change at least one of your fuse box's circuit breakers.
Lift your old cook top out of the counter top as though you were opening the hood of a car. Grasp it by the front edges and lift. Some cook tops have support pegs that can prop the cook top open. Scan the underside for a manufacturer's label that tells the amperage rating of the cook top. If there is no label or otherwise obvious means of determining the amperage of your current cook top, the safest way to proceed is to call an electrician. Alternatively, you can disconnect the cook top electrically and take it to an electrician for evaluation. Either way, it is essential to know the amperage rating of the cook top you are replacing.
Measure the hole in the counter top into which your current cook top fits. This is especially critical when replacing cook tops in granite counter tops.
Shop for cook tops that match the amperage of the cook top you are replacing. Unfortunately, many old coil-type cook tops use only 30 amps, while most modern, glass-topped ones demand 40 or 50 amps. This can mean you have to replace the 240-volt wiring to your kitchen and the 30-amp fuse and circuit breaker in your fuse box with those rated for 40 amps or 50 amps.
Replacing the wiring might be necessary because old 30-amp circuits typically used 10-gauge wire while the newer 40-amp and 50-amp ones call for 8-gauge.
Trip the circuit at your fuse box, and then in the kitchen use your electric line tester to make sure there is no current running in your 240-volt electric line. Using screwdriver and pliers, attach the wires from the new cook top to the 240-volt lines, following the wiring instructions supplied with the new cook top.
Drop the new cook top into the cook top hole in the counter top. Some models provide instructions for attaching the cook top to the counter top. Reset the circuit breaker at the fuse box. Turn on the new cook top to ensure that it is operating.