Water Heater Blanket or Jacket
When your water heater is not being used it is still storing hot water. And that's when it can lose heat through the walls of the tank if they are not well insulated. This loss is called standby loss since it is heat lost while the heater is standing by for use. It's the same concept as why you use an insulated travel coffee mug.
You can save 4% to 9% of your water heating bill and reduce stand by heat loss by 25% to 50% if you have an older water heater just by putting a sweater on it. Well, not really a sweater, but a blanket or jacket covering made of special insulation.
Older water heaters may not have come with an efficient amount of tank insulation. To see if your tank is a good candidate for a jacket, just touch it. It should not feel warm. If it does then the tank is not well insulated and a good candidate for this easy project. Look for a blanket with an R-5 to R-10 rating.
When installing, make sure to cut out areas so you can see safety markings and manufacturer data, thermostats and access covers. Leave a 2" clear cutout around the gas valve and access door to the burner. The Department of Energy has good instructions on installing an insulation blanket on an electric water heater: Installing a Blanket on an Electric Water Heater
Water Heater Blanket
