Bosch Induction Hob E3 — Wrong Cookware Detected Fix

What it means

Bosch induction hob E3 means the cookware on the zone is the wrong type or wrong size for induction.
Either the base isn't ferromagnetic (induction can't grip it), or the pan diameter is too small for the zone's coil to detect.
This is not a hardware fault — once you swap to a suitable pan, E3 clears in seconds.

Affected Models

Bosch Series 4 induction hobs (PUE/PUG models)
Bosch Series 6 PXE and PXX flexInduction hobs
Bosch Series 8 PXY perfectCook hobs
Bosch combi-hobs with FlexZone

Common Causes

Cookware base is aluminium, copper, glass, or non-magnetic stainless — induction can't couple to it
Pan diameter is smaller than the zone's minimum (usually 12 cm)
Warped or uneven pan base — the magnetic field can't form properly
Pan is off-centre on the zone
Old enamel or cast-iron pan with corroded base contact

How to Fix It

Do the magnet test.

Take a fridge magnet and press it against the bottom of the pan.
If it sticks firmly, the pan will work on induction.
If it doesn't stick (or only weakly), the pan is the wrong material — you need cast iron, magnetic stainless, or induction-rated cookware.
Check the pan diameter.

Bosch zones each have a minimum detectable pan size printed in the manual — typically 12 cm for standard zones, 14 cm for larger ones.
A small espresso pot or 10 cm milk pan won't trigger the zone at all and shows E3.
Move to a smaller dedicated zone or use a bigger pan.
Centre the pan on the zone.

Even an induction-compatible pan triggers E3 if it sits half off the zone.
Slide it so the base is centred over the cooking ring.
On FlexInduction zones, the coil follows the pan within the marked rectangle — keep it inside that area.
Inspect the pan base.

Run a hand across the underside.
If you feel a noticeable dip in the middle, the pan has warped and lost contact with the glass — induction can't read it.
Replace the pan; trying to flatten it usually makes the dip worse.

Frequently Asked Questions

Why does my old pan that worked before suddenly trigger E3?

Two common reasons.
First, the pan base may have warped from repeated heating-and-cooling — common on thin-base pans after a few years.
Second, the bottom coating has worn off, exposing aluminium that the magnet no longer sees.
Re-do the magnet test on a different part of the base to confirm.