Wednesday, January 14, 2009

Insulate a Hot Water Heater the Easy Way

While on the hunt for ways to reduce The Condo’s energy use, I did some poking around in my utility room. I found a big energy hog – my hot water heater.

Sure, I keep my hot water heater set at 120 degrees (F.) Set any higher and a hot water heater uses a lot more energy to heat water than I care to pay for and is a scalding risk. Set any lower and harmful bacteria can grow inside the hot water tank. That’s something you do not want.

 As like everything else that came with The Condo, the hot water heater was new but it is not Energy Star rated. I did some research and found that if I replaced my current practically new and working hot water heater with a comparable Energy Star model, I would only reduce its natural gas consumption by about $5-10 a year.

However, according to Popular Mechanics, I can save approximately 10% in yearly water heating costs if I insulated the hot water heater with a fiberglass blanket/jacket and insulated the water pipes leading from and to the hot water heater with insulated foam pipe sleeves.

Hmmm. Let’s see here. Spend $500 on a new Energy Star rated or tankless hot water heater (although I’ll admit they are kinda sexy) to save $5-10 a year in operating costs and generate a lot of extra energy and waste in delivering the new and removing the old but perfectly working model. OR, spend $30 and save 10% in hot water heating costs and generate little to no waste in the process.

Insulating the hot water heater and pipes wins hands down.

Insulated hot water heater or giant baked potato? You be the judge.

Renters, this energy and money saving project will work for you too because you can easily remove the insulation from the hot water heater and water pipes when you move.

How to Wrap a Hot Water Heater in an Insulating Blanket

This project is very easy. If you can put on a coat, you can do this project. Although I do recommend that two people do this project because most hot water heater blankets are big and a little unwieldy for only one person to handle

This project is also very inexpensive. I spent approximately $25 on materials and the project took me about a half an hour to complete.

The US Department of Energy recommends installing an insulated hot water heater blanket that has a minimum insulating value of at least R-8. The blanket I wrapped on my hot water heater has an insulating value of R-24 because that’s the only type the store had, so that’s what I bought. That’s OK, because in this case, the higher the R values on the insulated hot water heater jacket you use the better.

You will need:

Writing instrument

Tape (may come with your insulated blanket)


A friend

Do It!

1. Ask your friend to help you hold up the insulating blanket to the hot water heater.

2. Use the writing instrument to mark where the heating elements, thermostat, vents (if applicable), and burner (if your hot water heater is powered by gas) would be blocked by the insulating blanket.

You do not want to restrict airflow to these elements because in extreme cases, your hot water heater could explode like something out of Mythbusters. 

3. Cut out the areas you marked on the blanket with the scissors.

4. Wrap the insulated blanket around the sides of the hot water heater and secure it in place with the tape. Do not insulate the top of the hot water heater itself.

Caution: The insulation in the blanket is combustible. Be careful to keep the insulated jacket or blanket away from the drain at the bottom of the hot water heater, the flue at the top of the water heater, and near the burner.

5. Sit back and let the energy savings begin!

How to Wrap Hot Water Heater Pipes in Foam Insulted Sleeves

This project is also very inexpensive. I spent approximately $25 on materials and the project took me about 15 minutes to complete.

You will need:Pre-slit insulated pipe sleeves

Writing instrument

Tape (if your pre-slit insulated pipe sleeves are not already pretaped)


Do It!

1. Hold the insulted pipe sleeve up to the pipes leading to and from the hot water heater.

2. Use the writing instrument to mark where to cut the insulated pipe sleeve so it covers the length of the pipes leading to and from the hot water heater. Caution: be careful to keep the pipe insulation away from the flue at the top of the hot water heater or the pipe insulation may burn.

3. Use the scissors to cut the insulated pipe sleeve to fit the length of the pipes you are insulating.

4. Slip each water pipe into the slit in each length of insulated pipe sleeve and tape closed.


5. Celebrate with a cheap hot shower!

The beauty of this cheap and easy project is that I saw an almost immediate reduction of my natural gas bill after I insulated the hot water heater and its pipes, who knew?!

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Cathy said...

that's great--we've insulated our heater, but not the flue--we should do that.

Lisa Nelsen-Woods said...

No!!! Don't insulate the flue! It's too hot and may cause the insulation to catch on fire. That's why there's a one inch gap between the hot water heater pipe insulation and the hot water heater. I didn't want the pipe insulation to melt or burn because it is near the hot water heater flue.

Statewide Property Inspections said...

Keep up the good postings.

Anonymous said...

its ok to insulate the flue. but make sure that the insulator that you use is, heat resistance or fire resistance.

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