Insulating your hot water pipes reduces heat loss and can raise water temperature 2°F–4°F hotter than uninsulated pipes can deliver, allowing you to lower your water temperature setting. You also won’t have to wait as long for hot water when you turn on a faucet or showerhead, which helps conserve water.
Paying for someone to insulate your pipes—as a project on its own—may not make economic sense. But having the insulation done during new construction of a home, during other work on your water heater or pipes, or insulating the pipes yourself, is well worth the effort. In special cases, such as when the fuel used for heating water is very expensive, the distance traveled by the pipes is far, the pipes are exposed to very cold air (in which case they should be insulated anyway to prevent freezing), and if the household uses a lot of water, much higher energy savings can be obtained. In these cases, cost savings may offset paying for someone to do the job for you.
BEFORE YOU START
Determine the type of insulation material you want to use, how much you will need (length of the pipes), and the size of the pipe (match the pipe sleeve’s inside diameter to the pipe’s outside diameter for a snug fit).
For electric water heaters, pipe sleeves made with polyethylene or neoprene foam are the most commonly used insulation.
On gas water heaters, insulation should be kept at least 6 inches from the flue. If pipes are within 8 inches of the flue, your safest choice is to use fiberglass pipe-wrap (at least 1-inch thick) without a facing. You can use either wire or aluminum foil tape to secure it to the pipe.
Pipe sleeves or strips of fiberglass insulation from your hardware store
Acrylic or duct tape, or cable ties, to secure the sleeves—or aluminum foil tape or wire to secure the fiberglass pipe-wrap
If using fiberglass pipe-wrap, use gloves and long sleeves and pants
Scissors, box cutter or utility knife for cutting the insulation
Headlamp or light if working in crawl space or dark area.
Measure the pipes.
Starting at the water heater, measure lengths of insulation needed to cover all accessible hot water pipes, especially the first 3 feet of pipe from the water heater. It’s also a good idea to insulate the cold-water inlet pipes for the first 3 feet.
Cut the pipe sleeve.
Cut the insulation to the lengths needed.
Place the pipe sleeve.
Place the pipe sleeve so the seam will be face down on the pipe.
Secure the pipe sleeve.
Tape, wire, or clamp (with a cable tie) it every foot or two to secure it to the pipe.