Oven temperature fluctuates widely, sometimes too hot, sometimes too cold

Safety first: Disconnect power before accessing internal components.

• Verify with thermometer: Place an accurate oven thermometer inside and compare readings to the set temperature over time to confirm fluctuation.
• Check sensor mounting: Ensure the NTC sensor is firmly attached to the cavity wall and not hanging loose. Tighten mounting screws.
• Test sensor resistance: Measure resistance at room temperature and at a known elevated temperature (e.g., 100°C if possible). Compare to Sauter specifications. Replace if readings are unstable or out of range.
• Inspect wiring and connections: Tighten all element and sensor connections at the control board and terminal block. Loose connections can cause intermittent heating.
• Replace control board if needed: If sensor and wiring are good but temperature still swings excessively, the control board's regulation circuit may be defective and should be replaced.