In the wintertime, waterbeds use a lot of electrical energy to keep all that water at a comfortable temperature. While you are sleeping, they work like an electric blanket by keeping you warm no matter how cool the room gets.
Keeping your waterbed warm can save money by letting you lower the house thermostat way down at night. But, during the other two thirds of the day, waterbed heaters continue to use electrical power when no one is there to enjoy the warmth.
You can’t just shut them off to save money because it takes a very long time to warm all that water back up.
Minimize the energy waste by covering them up
Make your waterbed as soon as you get up. Your mom was right when she yelled at you to make your bed. Pile on the covers. The covers will insulate it, and save up to one-third of the power that the heater uses.
Add a bedspread or quilt on top to save more. It seems strange that you save money by insulating the bed for the two thirds of the day when you are not using it, but that is the way it is.
By making your waterbed disappear from sight under blankets or quilts, you insulate that big bag of water and slow the loss of heat. You are not covering up a problem you are insulating it to save your money.
Now go make your bed.