Hot Water Heater Efficiency Tips
Water use and electricity go hand in hand. Heating water can account for 14 percent to 25 percent of the total energy consumed in a typical home. What’s more, systems used to clean public water supplies and deliver it to homes require large amounts of electricity. If your home receives water from a well or spring, the pump also draws power. So when we use water, hot or cold, we’re also using energy.
Techniques for trimming water use in your home are surprisingly simple. For one, you can significantly reduce hot water consumption by simply repairing leaks in fixtures—faucets and showerheads—or pipes. A leak of one drip per second can cost $1 per month.
You can also reduce water heating costs in a matter of seconds by lowering the thermostat setting on your water heater. For each 10º F reduction in temperature, you can save between 3 percent and 5 percent in energy costs. Reducing the setting also slows mineral buildup and corrosion in your water heater and pipes.
Although some manufacturers set water heater thermostats at 140º F, most households usually only require them set at 120º F. However, if you have a dishwasher without a booster heater, you may require water temperature within a range of 130º F to 140º F for optimum cleaning.
Adding insulation to your water heater can save around 4 percent to 9 percent in costs. To determine if you need to insulate your water heater, touch it. A tank that’s warm to the touch needs additional insulation.
Insulating your water heater tank is fairly simple and inexpensive, and will pay for itself in about a year. You can find pre-cut jackets or blankets available from around $10 to $20 and install it yourself. Choose one with an insulating value of at least R-8. In addition, don’t set the thermostat above 130º F on an electric water heater with an insulating jacket or blanket—the wiring may overheat.
Installing insulation on gas- and oil-fired water heaters is more difficult. For these appliances, it’s best to have a qualified plumbing and heating contractor perform the work.
Insulating Water Lines
Insulating your home’s water pipes reduces heat loss and can raise water temperature 2-4 degrees Fahrenheit hotter than uninsulated pipes, allowing for a lower water temperature setting. You also won’t have to wait as long for hot water, which helps conserve water.
For exposed lines, such as in the crawlspace, or under a manufactured home, use pipe insulation foam to insulate the lines. Be sure to use the correct diameter based on the diameter of the pipes (i.e. if the diameter of the pipe is three-quarters inch, use the same size insulation). This will insure a tight seal around the lines. When installing foam insulation, do not leave any gaps where cold air could freeze the pipes.
For a home built on a slab foundation, you do not have to insulate the lines since they are covered by the concrete slab itself. But you do need to keep outdoor faucets protected for cold weather. An easy way to prevent the exposed faucets from freezing is fitting them with faucet covers, available at your local hardware store.
Installing Hot Water Heater Blankets
Water heaters can use a lot of energy even when you’re not using hot water. A common culprit is stand-by loss which occurs when heat travels and is lost through your water heater’s walls. One way to combat this is by using a water heater blanket, which adds an additional blanket of fiberglass insulation to reduce stand-by heat loss. To determine if you need a water heater blanket, place your hand on the tank itself. The tank should be room temperature, if the tank is warm or hot to the touch, then you need to install a water heater blanket.
Water heater blankets come in kits that contain a blanket, straps and tape for approximately $20 (Lowes and Home Depot). The straps hold the insulation the water heater and the tape seals the seams to the insulation.
Here are some tips about installing your water heater blanket:
- Turn the water heater off before installing the blanket. Read all the instructions that come with the blanket.
- Identify and wash the area of the water heater where the blanket will be taped, so the tape will stick.
- Cut the blanket to size with scissors or a sharp knife, leaving some extra until you know how much you will need.
- Identify the pressure relief valve on either the top or the side of your water heater. Don’t cover this important safety device.
- For electric water heaters, you can insulate the top of the tank as well as the sides. Note where the two rectangular covers provide access to the thermostats and elements. Cut small flaps in the insulation to provide access to these panels.
- For gas water heaters, don’t insulate the top. Note the gas valve and burner access door near the bottom of the tank. Cut the blanket so it is at least two inches away.
- Install the blanket so that it is snug, and fasten it well so it will stay in place.
This long-lasting conservation measure will save energy for the life of your water heater.