Você deve consultar o manual do proprietário do seu fogão lento. De acordo com um manual no site da West Bend:
There are five numbered heat settings on the heating base, 1 to 5. Heat setting # 1 should only be used to warm dinner rolls, muffins, etc. Heat setting # 2 should only be used to keep warm cooked foods for serving, whereas Heat Settings #3, #4 and #5 are to be used for actual cooking of foods. Set the dial directly at the numbered heat setting or midway between the numbered heat settings for complete temperature control. DO NOT USE A HEAT SETTING BELOW # 3 FOR ACTUAL COOKING OF RAW FOODS AS SLOW COOKER DOES NOT GET HOT ENOUGH TO COOK FOODS AT SETTING #1 OR #2. Set heat setting and cook food for recommended time as given in recipe. As a general guideline, most meat and vegetable combinations need 7 to 10 hours of cooking at Setting #3 (low), 4 to 6 hours of cooking at Setting #4 (medium) or 2 to 3 hours of cooking at Setting #5 (high).
Seu modelo específico pode ter instruções diferentes.