How to Insulate an Electric Water Heater Tank

gloved hands adjusting insulated water heater
  • 2-4 hours
  • Intermediate
  • 400-500
What You'll Need
Insulation kit (insulation blanket)
Measuring tape
Insulating pipe tape
Large scissors or utility knife
Dust mask
Marking pencil

An electric water heater tank is usually installed in your utility room, basement or garage. It keeps approximately 30 to 60 gallons of water ready for your disposal. However, it costs home owners a lot of money as it uses up more energy than one can imagine in order to keep the water warm all day. In order to cut down on your utility bills and save costs, insulate your water heater tank to better maintain the temperature. Listed below is a step-by-step guide to insulate your heater tank.

Step 1 - Clear the Area

Clear up the area around the electric water heater tank. Clean the top and exterior of the heater tank, or else the tape won’t grip securely. If the water heater tank is strapped to prevent it toppling, remove the strap prior to installation.

Step 2 - Measure the Water Heater Tank

Use a measuring tape to measure the height and the circumference of the heater tank. Add extra three to four inches to the measurement so when you cut the insulation so that there is enough coverage without compressing the heater.

Step 3 - Cut the Insulation Blanket

Roll out and place the insulation blanket on the floor with the plastic side facing up. Draw the measurements from step 2 on the blanket using a marking pencil. Cut the insulation blanket to size using a utility knife or a pair of scissors. Along one edge of the blanket, which will run from top to bottom of heater tank, cut away one inch of fiberglass batting from the plastic. The flap will be used to secure and overlap the blanket at a later stage.

Step 4 - Test Fit Insulation Blanket

Test fit the insulation blanket by wrapping around the heater. If it fits perfectly, use tape strips to hold the blanket in place. If it appears to be too loose, trim excess from the blanket’s edge, the edge where you did not cut the fiberglass battling in step 3, until it fits. Then, tape it securely closed.

Step 5 - Cut openings in the Blanket

Search for the heater’s control by feeling through the insulation blanket. Once you feel where the controls are, cut a three sided opening flap on the blanket with scissors. Leave the top of the flap uncut. You can now access to the controls and thermostat by lifting up the flap when needed, and the flap will fall back to its place when you are finished.

Step 6 - Insulate the Top of Electric Water Heater Tank

Measure the heater’s top diameter. Add extra inches to the measurement and cut a circle form from the remaining insulation blanket. The extra ensures you have overlap to tape down. Cut slots in the circle. This allows you to slide it onto the electrical cable and the pipes. Do not cover the relief valve. When all is fitted nicely, use tape strips to tape up slits, if any, and secure the insulation blanket onto the tank’s top.

Step 7 - Put Back the Strap

Put back the strap, if any, you have removed prior to insulating in step 1.