Add the carrots and onion to the bottom of the slow cooker.
Remove the chicken from its packaging. Remove any extra parts or packaging from the inside of the chicken. Drain off any liquid from the inside of the chicken.
Add the chicken on top of the vegetables.
Pour over the melted butter over the chicken.
Cut the lemon in half and squeeze over the chicken.
Sprinkle over the seasonings evenly.
Place the lid on the slow cooker.
Cook on LOW for 7-8 hours. This can vary for each chicken you cook, for they can vary in size. You know the chicken is done cooking when the drumsticks start pulling away from the breasts and the juices run clear. If you are concerned if your chicken is done, use a thermometer. 165° Fahrenheit is the safe temperature for chicken.
Should I add water?
There is no need to add water to a whole chicken recipe in the slow cooker.
Adding butter or lemon juice is better for infusing flavor. Unless you want poached chicken, do not add water. Adding water can make your whole chicken taste bland.
What instead can I use to raise the chicken out of the cooking liquid?The reason we place something like carrots and onion under the chicken is to keep it out of the cooking liquid so it doesn't turn into a soup. Try one of these methods if you prefer something other than carrots and onion.
Foil balls - You can take sheets of foil and ball them up. About 5 works well.
Small metal rack (such as the rack included in an instant pot)
Potatoes - Quartered potatoes also work well.
Does the slow cooker brown or crisp the chicken?
No, the slow cooker can not brown food for there is no browning element.
I use paprika to give a browned look for my whole chicken recipes.
You can put your slow cooked chicken under a broiler in an oven if you want crispy skin. Be sure your slow cooker is rated for such high temperature first, or place the chicken on a sheet pan.