Commercial oven not heating evenly — restaurant kitchen

Uneven bake in a convection oven usually comes down to four things — get them checked in this order:

1. Convection fan / motor — if it's weak or intermittent, hot air stops circulating and you get hot and cold spots. Most common cause of *sudden* unevenness.
2. Door seal (gasket) — a worn seal leaks heat on one side. Cheap to replace, often overlooked.
3. Failing heating element — if one element is dying, that zone runs cooler.
4. Calibration drift — the thermostat reads wrong; an oven thermometer inside will confirm actual vs set temperature.

Tell the technician "uneven bake, check fan and seal first" — it'll save diagnostic time. And put these on a preventive schedule; door gaskets and fan bearings are wear items in a busy kitchen.