Lower Your Water Heater and Insulate!

In the average American home, the water heater is the second greediest appliance in terms of energy use. Most people’s water heaters are set to 140°F without them even knowing it. But 120°F is plenty hot for a shower and also hot enough to kill any bacteria that could build up in your heater—plus, at this lower setting you’ll save a lot of energy.

What You Should Know

• Between 15-30% of the energy your water heater uses goes toward keeping a huge tank full of water hot at all times, in case you need it.
• The heat that escapes through the sides of the tank is especially important if it’s in an unheated spot like a basement or back porch. A water heater blanket can save 5%-10% of the energy you’ve been using, or approximately 465 pounds of carbon dioxide a year.
• Tankless electric water heaters are making their appearance in America these days in kitchens and bathrooms. They light up whenever someone turns on the hot water, and they heat the water as it passes through—so they don’t waste any energy keeping a tank hot.
• If half of the households in America turned down their water heaters by 10° F, we could prevent 239 million tons of carbon dioxide from being emitted each year.

What You Can Do

Turn the temperature of your water heater down to 120°F (or turn it to the “energy conservation” setting, if there is one). If you have an electric water heater with an upper and a lower thermostat, lower them both to 120°F.

Check to see if your dishwasher has a booster heater. These internal water heaters bring the water temperature up to 140°F, allowing you to get rid of tough grease while keeping the water heater for the rest of your home set at 120°F. Look in your owner’s manual to see if your dishwasher has one of these. If it doesn’t, you may want to leave your home’s water heater set at 140°F.

Wrap your water heater to make it more efficient. Put your hand on your water heater. If it feels warm, install an insulating blanket around it. The colder the area your water heater is in—often a basement or garage—the greater the heat loss. The same is true if your water heater is more than 10 years old. Coupled with insulating the pipes (see below), this simple step can reduce your annual hot-water bill by as much as 15 percent. The cost of the wrap and insulation will be earned back in savings within one year.

• Insulating jackets are available at your local hardware store for around $10.
• Be careful that the jacket does not block any air vents or cover the thermostat or flue.
• NOTE: If you have a relatively new water heater, it may have come installed with an insulating jacket.

Insulate exposed pipes. Insulating your hot water pipes will keep the hot water hotter in between hot water uses so that you will not have to wait as long for hot water. For longer runs in the house, especially in unheated parts of the house, your hot water will be hotter when it gets to the shower or faucet. You will be able to turn down your water heater even more if you are able to insulate all of your hot water pipes.

• It is recommended that you insulate three feet of both the hot and cold water pipes coming out of the water heater. The cold water pipe acts like a radiator on the hot water heater so it needs insulation too. The more you can insulate on the hot water pipe the better. This will save on heating up water and reduce the cooling between hot water usages.
• Insulate all the pipes you can access. This might get harder to do depending on what type of access you have to the pipes in the attic or under the house.
• Insulation is available at most hardware stores and is easy to install if you get the kind with the adhesive strip in it.

Turn off your electric water heater if you will be away from home for more than a few nights. It takes about four hours to reheat the water when you turn it back on.

Replace your old tank with an energy efficient one. When shopping for a new water heater, there are lots of factors to consider: what size you need for your family, what type and how energy efficient it is, which will also save you money. The US Department of Energy offers helpful descriptions of the different types of water heaters available and how to determine the right size and fuel source for your home. Be sure to check out the rebates for energy efficient water heaters that you may be eligible for.

Sources: You Can Prevent Global Warming: 51 Easy Ways, by Jeffrey Langholz and Kelly Turner; 30 Simple Energy Things You Can Do To Save The Earth, by the Earth Works Group and PG&E; Rebuilding Together Energy Team Guidebook January 2002, by Dr. Lisa Gartland; Green Action Guide; the Green Team Project; Acterra (David Coale).