Induction Cooktop Not Heating: What to Check

Induction is the one cooking surface that can be in perfect working order and still refuse to heat. It is not being difficult — it is refusing to transfer energy into something it cannot couple to. Roughly half of the “not heating” calls we take on induction end without a part being fitted.

Work through these in order. They are arranged by how often each one turns out to be the answer, not by how technical it sounds.

1. The pan

Induction heats the pan, not the surface. The pan must be ferromagnetic and it must sit flat.

Hold a fridge magnet to the base. If it does not grab firmly, that pan will never work — no fault, no fix. Most stainless is partly non-magnetic; aluminium and copper without an induction disc are out entirely; some very good tri-ply pans have a base that has warped enough to break contact in the middle.

There is also a minimum diameter. A small espresso pot on a large zone frequently will not be detected at all, and the cooktop will flash a detection symbol and shut the zone down after a few seconds. That is correct behaviour.

2. One zone, or all of them?

This single question splits the diagnosis.

One zone dead, the others fine. The fault is local to that zone — its induction coil or the power module driving it. A full-surface Thermador Freedom-type cooktop complicates this slightly, because the zones are virtual and a module serves an area rather than a circle, but the principle holds.

Every zone dead, panel lit. The control board has power but the power stage does not. The usual cause is not the cooktop at all.

3. The power feed — the most common whole-cooktop cause

An induction cooktop is normally fed by a 240V circuit using both legs of the supply. If one leg is lost — a tripped half of a double-pole breaker, a loose lug in the panel, a failing breaker — the control electronics often still come up on the surviving leg. So the touch panel lights, it beeps, it accepts settings, and nothing heats.

The tell is exactly that combination: a fully responsive display with no heat on any zone. Check the breaker: reset it fully off before back on, since a half-tripped double-pole breaker does not always look tripped. If it trips again, stop and get the circuit looked at.

4. Cooling and thermal shutdown

Under every induction surface is a fan and an air path. If that path is blocked, the electronics overheat and the cooktop protects itself by cutting power to the zones while the display stays alive.

Two things block it. Dust and grease in the intake — common on installations over five or six years old. And the appliance underneath: an induction cooktop over a wall oven or a warming drawer needs its specified air gap, and a cabinet that was tightened up during a renovation can close it.

The pattern to look for is heat that works for a while and then stops, especially during a long roast or a full dinner. That is thermal, not electrical.

5. Residual heat and lockouts

Two non-faults that get reported as faults. An H on the display is residual heat from the pan warming the glass back — it will clear on its own. And a lock symbol means the child lock or the control lock is on, which the manual will tell you how to release for your model, usually a press and hold on a key pad.

6. When the glass is the problem

A crack in the ceramic surface, even a fine one, takes the cooktop out of service. Moisture reaching the coils underneath is a shock risk. If the glass is cracked, switch the circuit off at the breaker and do not use it, whatever the display says.

What is actually repairable

Power modules, coils, fans, temperature sensors, touch boards and wiring are all serviceable parts on premium induction equipment. The glass is replaceable on many models but the economics depend on the unit. Cooktop repairs generally run $200 to $750 including parts and labour, with control-board work toward $400 to $850. The $95 diagnostic is credited toward the repair and the work carries a 1-year parts and labor warranty.

Before you call

Have three answers ready: does a magnet stick to the pan, is it one zone or all of them, and does the display respond normally. Those three facts get an induction diagnosis most of the way home over the phone.

Call (914) 809-9382 for induction service in Larchmont and the surrounding Sound Shore.