How to Insulate a Hot Water Pipe and Save More Energy

Insulating hot water pipes is one of the easiest ways to save energy and money in the household. Estimates show that insulating as a DIY project will pay for itself in about a year, so why not give it a shot? The pipes that come out from your steam or hot-water boiler and from a water heater emanate heat just like a baseboard or a traditional radiator. If you spend a lot of time in the same space as your water heater, the heat may be a welcome factor. But if you’d rather do without the heat loss from those pipes, you might want to check out this guide on how to insulate a hot water pipe.

According to the U.S. Department of Energy, insulated hot-water pipes can significantly decrease heat loss. They can also keep the water inside them 2-4°F higher than uninsulated pipes. Another added benefit is that your water heater will no longer have to drench and reheat the pipes each time you run hot water during periods of peak usage. Fortunately, setting up this home improvement project is not just easy to do, but it’s also inexpensive. The following steps will help you start saving energy and money today.

Why Go with DIY Insulation

You should know from the start that hiring a professional to insulate your hot water pipe is hardly worth it. Doing this project by yourself, on the other hand, makes much more sense. It costs very little and comes with a great financial return on investment. Expect to pay around $10 in materials and save about $10 per year. Therefore, insulating your pipes has a one year payback. In addition to the financial benefits, there’s also the fact that the hot water in the pipes will remain warm longer between uses. Insulation is also much cheaper than installing and maintaining a hot water recirculation pump.

Before You Start

Decide on the type of insulation material you will need. Determine the length of the pipes and the size of your pipes. Make sure the pipe sleeve’s inside diameter matches the pipe’s outside diameter; a snug fit is the best way to go. For electric water heaters, the most commonly used insulation is pipe sleeves made from neoprene or polyethylene.

If you’re insulating the pipes of a gas water heater, make sure the insulation is at least 6 inches away from the flue. You can also stay safe with pipes that are within 8 inches of the flue by using fiberglass pipe-wrap without a facing. Secure the insulation to the pipe with either wire or aluminum foil tape.

What You’ll Need

  • Tape measure
  • Pipe sleeves or strips of fiberglass insulation (available at hardware stores)
  • Duct tape or cable ties (for securing the sleeves)
  • Long sleeves and pants are required if using fiberglass pipe-wrap
  • Box cutter/utility knife (for cutting the insulation)
  • Proper light if working in dark area or crawl space.


  1. Measure the hot water pipes – Start at the water heater and measure the lengths of insulation needed to cover all accessible hot water pipes. The first three feet of pipe from the water heater are essential.
  2. Cut the pipe sleeve – Cut the insulation to the lengths you have already measured.
  3. Set the pipe sleeve – The pipe sleeve should be placed so the seam will be face down on the pipe.
  4. Secure the pipe sleeve – To secure the insulation, wire, tape, or clamp (with a cable tie) it every foot or two.

Useful Tip: When you’re insulating the pipes leading to and from your hot water tank, keep in mind the insulation shouldn’t come flush with the tank. For safety, leave some space between the contact point between the pipes and the tank. If they’re flush with each other, your insulation could create a potential fire hazard.

Alternative Method: Pipe Insulation Foam

  • Pipe Insulation (both 3/4″ and 1/2″)
  • Measuring Tape & Sharpie
  • Zip Ties or Silver Tape
  • Scissors/Box Cutter
  • Dust Mask, Gloves, Protective Eye Wear
  1. Turn off the power to the hot water tank. You should find the controls in your home’s circuit breaker. Once you’ve found the switch, turn it to the off position.
  2. Measure the various lengths of piping insulation needed with your tape measure. Be sure to take note of any angles you’ll need to accommodate. The diameter of the pipes is also important when it comes to foam insulation.
  3. Cut the insulation to the required lengths. Use a box cutter, utility knife, or scissors to cut the foam insulation. Once again, be sure to cover any angles and connections in the piping. It’s better if you leave your cuts a little longer than necessary (to start off).
  4. Pick a starting point along the pipes to place the insulation. As you advance, you’ll need to trim some of the pieces for a snug fit. Also, double check that you’re not leaving space between the pipe and insulation. Doing so will render the insulation significantly less effective.
  5. One by one, take off the pieces of adhesive tape from the seam of the insulation. Then, simply place the piece of insulation back as it was, snugging the desired pipe. Press the seam so it sticks together. This way, your hot water pipes will be ensured with a good seal around them.
  6. Take your silver tape and use it to secure the insulation in place. Place a generous strip around the foam insulation every one foot or so. Meanwhile, make sure you cover any connections between pipes with an extra strip. This will ensure a good seal on the insulation.
  7. Now that you’re done with your DIY insulation project, it’s safe to turn the power to the hot water tank back on. Perform one last check on your foam insulation, making sure every piece is in place and does its job. And you’re done and ready to save energy and money!

Some will argue that the savings from insulating a hot water pipe are not worth it. We recommend this DIY project for both old and new houses. For old houses, insulation will reduce the heat loss. For new ones, it will set the homeowners on the path for a green home from the get go! Let us know what you think about hot water pipe insulation in the comments below. 

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William E. Eubanks

I'm one of the main writers on the site; mostly dealing with environmental news and ways to live green. My goal is to educate others about this great planet, and the ways we can help to protect it.

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