If the water heater you use is located in a space like, (a garage, basement, or attic) and you dont want to add heat, you could use a heavy blanket. But not just any blanket. An insulation type blanket is not really for use on a water heater located where its lost heat could be used. Neither is a blanket necessary if your water heater is new that is, covered with R-16 insulation. (The factory insulation is fitted between the shell and the tank, so dont worry if you cant see it.) The makers tally will tell you how much insulation your water heater contains. Dagenham Plumbers can give professional advice and service.You buy a water heater insulating blanket as a kit for the size of the heater for instance, 30, 40, or even 50 gallons. The kit contains a blanket thats finished with white vinyl on the outside and raw insulation on the inside and enough adhesive tape to finish the seams. A Dagenham Plumber fits this kit.How to wrap your water heater with a blanket:If yours is a gas water heater:?Wrap it all the way around and from the top to just a little below the controller. Dont panic if the blanket seems a little short. The tank bottom is quite a few inches above the bottom of the heater, and 2 or 3 inches below the drain valve. Do not use it on the top of a gas fired water heater as the insulation may cause a fire fire from the heated exhaust. Also, this insulation blanket should not be covering any of the following: The controller, anode or the pressure and temperature relief valve.If yours is an electric water heater:?As these heaters do not provide any exhaust gas, you may use this type of insulation on its sides and top. However to prevent electrical components from overheating, do not cover any covers for the element.