DIY Network

How to Insulate an Outdoor Water Heater

These steps demonstrate how to separate and insulate an outdoor water heater and its pipes in order to prevent a bulge in the adjacent wall.

More in Remodeling

  • Time


  • Price Range

    $1 - $50

  • Difficulty

    Moderate to Hard


Step 1: Separate the Water Heater

Turn off the water to the water heater. Next, attach a garden hose to the drain and drain all the water out of the tank. While the tank drains, unscrew any earthquake safety straps. Turn off the gas, and disconnect the water lines.

Unscrew the flue from the water heater, but leave the draft inducer intact. Remove the water heater: Remove the housing (cabinet), unscrew the wall anchors and pull the water heater away from the wall.

Step 2: Insulate the Water Heater

With the water lines exposed, measure and cut a piece of rigid foam insulation to size. This will fit between the wall and the water lines and will be completely covered by the water heater housing.

Slide the piece into position and push gently against the wall anchor screws.

Step 3: Insulate the Pipes

Measure and cut the foam pipe insulation to size. The insulation should be the same length as the pipe. Cut a slit along the foam down the entire length of the pipe. Once split, slip the foam insulation around the water pipes.

Drive the screws back into the wall anchors to secure the pipes in place. Put the water heater back in place. Replace the flue, and hook up the water and gas lines. Light the pilot light.