Water-heater blankets reduce standby losses. Water heaters that are more than ten years old usually have only one inch of built in fiberglass insulation (about R-3), which is not really sufficient to control heat loss. Adding a blanket to these older tanks will cut consumption by 5 to 10 percent. Newer water heaters usually have two or three inches of foam insulation (R-10 to 15), which reduces standby loss by multiples. Adding a blanket to newer tanks is still a good idea, but it will have less of an impact than on older tanks. On older tanks, you'll recoup the cost of a blanket in a year or less; on newer tanks it may take a few years.
Inspect your water heater to see if the R-value of its built-in insulation is listed on a yellow Energy Guide label or on the maker's data plate. If the R-value is not listed, the tank is probably old enough to have no more than R-3 insulation.
Water-heater insulation blankets are available in most hardware stores for $10-$20. Choose one that is at least 3 inches thick, or listed as R-8. These blankets are fairly easy to install if you are comfortable working with hand tools. You'll need a tape measure, a sharp knife, and a pair of scissors for this project.
When you are done, make a final inspection to confirm that you've left proper clearances around the pressure relief valve, the drain, the thermostat and chimney if you have a gas heater. Turn the electric or gas service back on.
Tags: tankless water heater, solar water heater, hot water heaters, tankless hot water heater, hot water heater, gas water heater, electric tankless water heater, electric water heater.