Induction and electric cooktops: dead zones, pan detection

Induction is the quietest appliance in a Clay County kitchen until it is not. There is no flame to look at and no burner to reseat, so the diagnosis is electrical from the start — but it is still mostly a heat-management problem, which is the part people miss.

One zone dead is a good sign

Counterintuitive, but true. Each zone has its own coil and its own power stage. When exactly one zone stops working and the rest of the cooktop behaves perfectly, the shared supply and the shared user interface have both just proved themselves. The fault is in that zone’s coil, its power module, or the ribbon between the module and the control.

When every zone dies at once, the suspects invert: the supply, the interface, or the thermal protection that shuts the whole unit down.

Pan detection is not a fault by itself

A cooktop that refuses a pan is usually right. Induction needs a ferrous base with enough contact area, and a warped base lifts the centre away from the glass. Cookware that worked for years can stop working after it has been dropped or run dry once too often.

Detection that fails across every pan on every zone is a different matter and points at the sensing circuit or the control.

Heat is the real enemy

An induction cooktop cools itself. Underneath the glass there is a fan pulling air through the electronics, and it needs a clear intake and a clear exhaust path in the cabinetry.

Two local habits break this. The first is a drawer stack or a base cabinet retrofitted under a cooktop with no clearance left for airflow. The second is an installation over a wall oven where the oven’s own exhaust rises straight into the cooktop’s intake. In both cases the symptom is identical and misleading: everything works for five or ten minutes at high power, then zones drop out one at a time and come back once the unit cools. That is thermal protection doing its job, not a failing coil.

A fan that runs constantly, long after cooking, is often reporting the same condition from the other direction.

Storms, again

Sixty-eight thunderstorm days a year in this county land squarely on cooktop electronics, and an induction unit has more of them to lose than a radiant one: an interface board, a power stage per zone and the cooling fan that keeps both alive. The failures are rarely immediate. After the long outages of 2016, 2017 and 2024 the pattern was the same each time — zones dropping out or a dead interface weeks later, in units that had worked since the power came back.

Glass

Cracked glass is not repairable and is not safe to keep using. A crack lets liquid reach the coils and the electronics beneath, and on a bridged or full-surface zone it changes how the field is contained. The honest answer, delivered on the first visit, is what a replacement surface costs against the value of the appliance — some are worth it and some are plainly not.

The visit

Supply and both legs at the appliance, then interface response, then per-zone coil and module testing, then clearance and airflow in the cabinet. That last step is skipped by most people and is the reason a replaced module fails again the same summer.

Written estimate before parts. Genuine OEM parts, 90 days on labor, 365 days on parts.