Intrigued? Read on to learn how you can get your water heating costs down. Do you want to see how much your leaky faucet is costing you? The American Water Works Association has a drip calculator you can use to find out. E​nergy.gov has instructions on how to insulate water pipes. Not sure where your owner’s manual is? Put your hands on the outside of the tank, and if it feels warm, you don’t have enough insulation. When installing an insulation blanket, it’s important to know how to insulate a water heater tank the right way and don’t cover certain parts of the hot water heater.