La Cornue “Er” Oven Error
La Cornue “Er” Oven Error is a common question among La Cornue owners. This guide walks through it step by step with technician-grade detail.
An “Er” code (often “Er” followed by a number) on a La Cornue electronic or multifunction oven signals an internal technical fault that the control has detected. Unlike a user error, this one generally needs service. This guide explains what to do.
What “Er” indicates
“Er” is the control board’s way of reporting an internal fault — commonly a temperature sensor that has gone open or short, a communication error between components, or another electronic problem. The accompanying number narrows down the area, though interpretation typically requires service documentation.
First steps you can take
- Power cycle: Turn the oven off at the breaker for a minute, then restore power. A transient glitch sometimes clears.
- Note the exact code: Record the full “Er” code and number, and what you were doing when it appeared. This speeds diagnosis.
- Stop using the oven if the code persists, especially if temperatures seem wrong.
Common underlying causes
- Sensor open/short: A failed temperature sensor reports impossible readings, triggering the fault. The fix is sensor replacement — related to the symptoms in our temperature drift guide.
- Convection fan fault: On convection ovens, a fan or its circuit can trigger a fault — see our convection fan guide.
- Control board issue: A board-level fault may need board service.
Why this usually needs a technician
Pinpointing an “Er” fault requires measuring sensor resistance, checking wiring continuity, and interpreting the code against service data. These are not user-serviceable steps, and guessing at parts wastes money. A technician can read the fault, test components, and replace the right one.
Repair, not replace
An “Er” fault is almost always a component-level repair (sensor, fan, or board) — not a reason to replace the oven or range. For perspective, see our repair cost guide.
Professional service
Record the code and schedule a technician. You can also reference your model’s documentation on lacornueusa.com or contact the National Service Center.
Write down the full code first
The most useful thing you can do before calling for service is record the exact code — “Er” plus its trailing number — along with what the oven was doing when it appeared (preheating, mid-bake, on convection). The number narrows the fault area, and the context helps the technician interpret it against service data. A quick power cycle at the breaker for a minute sometimes clears a transient glitch; if the code returns, stop using the oven, especially if temperatures seem wrong.
Why guessing at parts wastes money
An Er fault commonly traces to a temperature sensor that has gone open or short, a convection fan or its circuit, or a control-board issue. These are not visually obvious, and pinpointing them requires measuring sensor resistance and checking continuity against the code. Buying a sensor or board on a hunch often replaces the wrong part. A technician reads the fault, tests the components, and replaces only what failed — which is also why an Er is a component-level repair, not a reason to replace the oven. See our repair cost guide.
Frequently asked
- Will calibration fix an Er? No — a failed sensor must be replaced; calibration only helps a working-but-offset thermostat.
- Could it relate to the convection fan? Yes — a fan or its circuit can trigger a fault; see our convection fan guide.
First steps and why it is a repair, not a replacement
When Er appears, power-cycle the oven at the breaker for a minute in case a transient glitch caused it, record the full code and number, and stop using the oven if the code persists or temperatures seem wrong. The underlying cause is almost always component-level — a temperature sensor gone open or short, a convection fan circuit, or a control-board issue — and each is individually serviceable, so an Er fault never justifies replacing the oven or range. A technician reads the fault, tests the components, and replaces only what failed; see our repair cost guide.
