Electric main oven heats but never reaches set temperature or takes excessively long to cook food.

Safety first: Turn off power before removing panels.

• 1. Compare with another oven: If your Rangemaster has two ovens, compare preheat times. A significantly slower oven suggests a heating issue.
• 2. Check which elements heat: With the oven on, carefully feel (without touching metal) for heat from the rear, base, and top. A cold area may indicate a failed element.
• 3. Inspect door seal: Look for gaps, tears, or flattened sections in the door gasket. Replace if not sealing evenly.
• 4. Test elements: With power isolated, measure resistance of each element (fan, base, top). Replace any that are open circuit or significantly different from specification.
• 5. Thermostat check: Use an oven thermometer to compare actual temperature to the set value. If consistently off by a large margin and elements are good, the thermostat or sensor may need replacement.