Induction or ceramic cooktop not heating — why, and what to do

You put a pan down, switch on the zone, the panel lights up — but the base stays cold. Or it heats for a minute, beeps, and shuts off. Or only three zones out of four work. Or a crack runs across the surface. These are four completely different faults with different causes, and before you weigh up a repair you need to know which cooktop you actually have — induction or ceramic. They heat on different principles and they fail differently too.

This is an honest read from the bench: how to tell the two types apart, what you can check yourself, where the electronics begin that only a service centre may touch, and when one live part solves the problem versus when it is a surface swap or a new cooktop. Electric cooktops only — induction and ceramic. No gas cooktops here.

First work out which one you have — induction and ceramic fail differently

From the top they look almost identical: a smooth dark ceramic-glass lid with no exposed coils. But inside they are two completely different machines.

An induction cooktop does not heat the surface itself. Under the glass sits an induction coil that creates an alternating magnetic field; it induces eddy currents straight into the base of the pan, and the pan heats, not the panel. That is why it needs ferromagnetic cookware — a steel or cast-iron pan whose base a magnet sticks to. All the power runs through an IGBT module (a power transistor) driven by the control board. When something is wrong, induction usually does not stay quiet — it beeps and shows an error.

A ceramic (radiant) cooktop is simpler. Under the glass, each zone has a coiled heating element that simply glows red and heats the glass, and the glass heats the pan. Any pan with a flat base works here. Power is shared by an energy regulator (simmerstat) or electronic control. There is less complex electronics here and more often simple, physical failures: a burned-out element, a jammed regulator.

The simple test if you are unsure: place a magnet on a cold zone and try to heat a glass of water in an aluminium or glass pan. If the magnet sticks to the base and the aluminium pan does not heat, it is induction. If any pan heats and the zone gets hot even with no pan on it, it is ceramic.

Nothing heats at all — power supply and control board

If no zone responds, think about the power supply first, not the cooktop.

Powerful cooktops in Riga flats are often wired to a separate line and their own breaker. Check the distribution board: has the breaker tripped, has the RCD tripped? In older Riga buildings with tired wiring, the inrush load of an induction cooktop can trip the breaker — if that repeats regularly, the problem is in the line or the protection, not just the cooktop. You or an electrician check that, not us.

If the power is fine but the panel is completely dead — no indicator lit, no beep — the inside comes next:

• The mains relay on the board — the part that connects the whole appliance to the mains. Burnt contacts are a typical failure; the cooktop looks "dead".
• The power supply / control board — bulged capacitors, burnt traces, bad solder joints. Often the culprit is years of heat and damp right under the surface.
• The induction IGBT module — the most commonly damaged power part on induction. When it is blown, the cooktop either does not react or throws an error and shuts off straight away.

This is where self-help ends. You can check the breaker and the cookware with a clear conscience. But inside the cooktop's power supply there is mains voltage and charged capacitors — do not take the casing off. If the power is good but the panel stays silent, the next step is the bench — bring it in.

One zone is dead, the rest work

This is the most favourable fault you can get — one zone does nothing while the rest heat normally. It nearly always points to a part of that zone, not the whole cooktop.

The diagnosis differs by type:

On a ceramic cooktop a dead zone is most often exactly a burned-out radiant heating element — a separate, replaceable part. It is often worth repairing: one element or regulator restores the zone and the cooktop keeps going. On induction a dead zone usually means that channel's coil, the thermal sensor on the coil, or the zone IGBT — trickier, but still often a local repair rather than swapping the whole board.

There is almost nothing for you to do here, except one thing: make sure the problem follows the zone, not the pan. Move the same good pan onto the "dead" zone and a good pan onto a working one. If the fault stays with the zone, it is the cooktop. Bring it in; which part to change is decided by inspection.

It heats, then shuts off after a minute (overheating, fan, cookware)

The cooktop starts up normally, but after a minute or a few it beeps and switches the zone off. This is almost never random — something is making the protection trip.

The most common causes, from simplest to more serious:

1. Wrong or warped cookware (induction). If the pan base is not flat or not truly ferromagnetic, the cooktop strains, overheats, and protects itself by shutting the zone off. Check with a magnet and with an obviously good, heavy steel pan.
2. A clogged cooling fan (induction). The IGBT module and coil produce heat; a small fan cools them through air vents under the cooktop. In built-in cooktops, dust and grease build up under the surface over years. If the fan is not running or the vents are blocked, the electronics overheat and shut off after a minute — that exact pattern.
3. The thermal sensor on the coil (induction) or the surface thermal limiter (ceramic). If the sensor is damaged or the leads are loose, the board "sees" a false overheat and shuts off for safety.
4. A poor mains connection. An intermittent hot contact in the terminal produces heat and a voltage drop under load; the protection can trip.

Self-check: clear the underside air vents of dust, listen for whether the fan starts, and try a definitely good pan. If after that the cooktop still shuts off after a minute, checking the sensor, fan, and board needs the bench. Bring it in; do not open the inside.

Error symbols — what the broad categories mean (no pan, overheating, voltage)

Induction cooktops show errors as symbols or alphanumeric codes, and each manufacturer has its own. We will not name a precise code — because they differ, and inventing them would mislead you. But every code falls into a few broad categories, and the category can be understood without the manual:

• "No pan" / pan not detected. Induction is looking for a ferromagnetic base. The culprit is most often the cookware (aluminium, a thin base, too small for the zone), not the cooktop. Check with a magnet first.
• Overheating. The inside or the surface has got too hot — see the previous section: fan, sensor, cookware.
• Voltage error. The cooktop sees a voltage that is too low or unstable and refuses to run to protect the electronics. In older Riga buildings with weaker wiring the voltage sags under load, and induction in particular is sensitive to it.
• General internal error. Communication between the control panel and the power board has broken — usually a board-level or ribbon-cable failure.

What you can try yourself: fully disconnect the cooktop from the mains for a couple of minutes (trip the breaker), then switch it on — this clears a short-lived glitch. Check the cookware and the vents. If the code comes back at once or after a minute, it is no longer a random glitch — the next step is diagnostics.

Cracked or chipped glass — when it is a surface swap, when it is scrap

A ceramic-glass surface is tough against heat but brittle against impact and point load. A crack usually comes from a dropped heavy pan, from a pan knocked against the edge, or from a sharp temperature difference (cold liquid on a hot zone).

There is a clear line here:

• A crack or chip in the glass only, with the electronics and elements intact — that is a surface swap. On many Bosch, Siemens, Electrolux, AEG, and Whirlpool cooktops the ceramic-glass lid is a separate, detachable part. If the surface can be sourced for your model, the cooktop comes back to life.
• A crack right through, with steps or a crumbled corner — do not use the cooktop. Liquid and steam get under the glass through the crack; they reach the elements, coils, and electronics and cause a short circuit. On induction a cracked glass is especially dangerous, because there is a live coil under it.
• The glass is whole but scorched or worn on top (matte patches around the zone) — that is cosmetic, not dangerous; replacement is usually not worth it.

When is it scrap? When the crack has also injured the electronics or the elements, or when the surface for that specific old model is no longer made. Then sourcing and fitting a new surface costs comparably to the whole cooktop, and the honest thing to say is — time for a new one.

Yourself: if the glass is cracked through, disconnect the cooktop from the mains and do not use it until inspection. Whether the surface can be sourced for your model, we find out at diagnostics — that is the deciding point between a repair and a replacement.

Repair or replace — decision table

A cooktop is not a cheap appliance, so the "fix or buy new" decision is real. This table sums up where, in our experience, a repair usually pays off and where it does not. The comparison is qualitative — we identify the fault on-site.

The simple principle: if one local part is damaged and the casing with the glass is intact, a repair is almost always cheaper than a new cooktop. If several things fail at once — cracked glass plus damaged electronics plus high age — the balance tips toward replacement, and we say so plainly at inspection.

The cooktop diagnosis and repair itself is covered by our home appliance repair service.