A slow cooker, crockpot, is used for unattended slow cooking meals/dishes. Boiling or heating water is not the function of same. Most of the newer appliances run very hot, and cooking for 12 hours is way too long. To clarify, I bought mine (Rival programmable about a decade ago). Hamilton Beach sounds like a good brand. Experiment with it. I think that Crockpot is actually a trademark name.
I suggest reading the manual, and experimenting with your brand. I suggest browning searing meat first. Once you learn how to use your brand, there are many creative ways to utilize same - from "baking" bread to seafood, to tomato sauce to steaming artichokes, and on and on. Mostly, I've used it for tomato sauce, and plunked my meatballs in there. Beef Bourgignon is another way to go. Just watch it carefully & don't cook too long.