Water Heaters: 5 Tips for Saving Energy
By: Joe Bousquin
Published: November 5, 2010
Your hot water heater eats energy: We want to reduce its appetite. Here are inexpensive things you can do to increase efficiency and cut energy bills.
Saving Energy Tip #1: Wrap your heater in a blanket
Your water heater needs a blanket in the winter to stay warm, especially if it lives in an unheated space. A fiberglass insulating blanket can cut heat loss by 25% to 40% and save 4% to 9% on the average water-heating bill of $308, says the American Council for an Energy Efficient Economy (ACEEE).
Insulating blankets are easy to install and inexpensive ($30). When dressing your tank for saving energy, be careful not to block the thermostat on an electric water heater or the air inlet and exhaust on a gas unit.
Many newer units already contain insulating foam, making a blanket unnecessary and even hazardous; it can block critical components. Check with your manufacturer.
Saving Energy Tip #2: Install low-flow fixtures
One sure way to cut hot water costs is to use less of it.
The ACEEE says a family of four uses 700 gallons of hot water per week. Install low-flow shower heads and faucet aerators ($10 to $20 each) and cut hot water consumption by 25% to 60%, typically $200 off the average U.S. household water bill of $475, according to the U.S. Environmental Protection Agency.
Also, make sure you use the “economy” setting on your dishwasher, and break the pre-washing habit. Modern dishwashers can handle a dirty dish. Scrape what’s left of dinner into the trash and then load.
Saving Energy Tip #3: Take your water heater’s temperature
Your water heater probably came from the factory with its temperature set high. For every 10 degrees you turn it down, you’ll save 3% to 5% on your bill. A setting at 120 to 140 degrees is hot enough. Just don’t go below 120 degrees, which could lead to bacteria growth inside the tank.
If the thermostat on your water heater doesn’t have a numbered gauge, put it midway between the “low” and “medium” marks. Wait a day, and then measure the tap temperature with a cooking thermometer. Keep adjusting until you hit your target temperature.
Saving Energy Tip #4: Drain the sediment
Tanks naturally build up sediment, which reduces efficiency and makes saving energy a challenge.
Draining the tank and saving energy is relatively easy. Turn off the water and power to the unit (set the burner on a gas unit to “pilot”). Connect a garden hose to the spigot at the base of the tank. With the other end of the hose pointed at your floor drain, carefully lift the tank’s pressure-relief valve and turn on the spigot; water should begin to flow.
While most manufacturers recommend draining the tank once or twice a year, you don’t have to drain it completely; in fact, the Department of Energy recommends draining less water more often—just a quart every three months.
Saving Energy Tip #5: Insulate exposed hot-water pipes
Like blanketing the tank, wrapping insulation around hot-water pipes reduces standby losses. Water arrives at the tap 2 to 4 degrees warmer, which means you won’t have to wait as long for it to heat up, thus saving energy, water, and money.
While this isn’t an expensive DIY job—6-foot-long, self-sealing sleeves ($2.50) easily slip over pipes—it could take effort, depending on where your hot water pipes are located. Exposed pipes in the basement are an easy target: hard-to-reach pipes in crawl spaces or walls might not be worth the trouble.