Saving Energy With Water Heating


Water heating is one of the largest single contributors to home energy bills, often as much as 25% or more, and one that is often ignored. There are a number of simple things you can do to reduce your water heating expenses and many of them will also help reduce your water bills.

The cost of heating water depends mainly on the amount of hot water used in the home and the water heater's thermostat setting.

Reducing Hot Water Use


Showers and Baths

In many cases, showering can be the largest single contributor to water heating costs. Even a relatively short 10-minute shower can use 50 gallons or more with an older inefficient showerhead.

  • Install a new low-flow showerhead to reduce the flow rate by half or more, without sacrificing the "feel" of the shower. There are a wide variety of low-flow showerheads available, including hand-held and massage types. Installation is usually a quick and simple job (assuming you are able to remove the old one).
  • Take shorter showers.
  • Take showers instead of baths - a shower can use as little as one-third the hot water as a tub bath.

Laundry and Dishwashing

Laundry and dishwashing are also major contributors to overall water heating costs. Here are a few simple tips to help save energy and money.

  • Use the lowest temperature wash and rinse settings for clothes washing. Using cold water not only saves energy and money - it can also reduce fading and shrinkage.
  • Run full loads in clothes washers and dishwashers. For dishwashers, the amount of water and energy is the same for a small load as a full load. With clothes washers, use the appropriate setting for the size of the load.
  • Don't pre-rinse dishes in hot water - just wipe off any food with a paper towel or napkin.

Miscellaneous Uses

  • Don't run the water constantly while shaving or washing.
  • If you hand wash dishes, fill the sink or a basin with hot water, rather than leaving the water running.

Fix Leaks in Hot Water Pipes

  • A leaky faucet can waste as much as 3,000 gallons a year. If the leak is in a hot water pipe or faucet, you could save roughly 440 kWh per year with a typical electric water heater, and about 25 therms per year with a gas water heater.

Reducing Hot Water Temperature

You can easily check the temperature of your hot water with a thermometer at a faucet close to the water heater. Set the thermometer in a glass or cup and run the hot water until the temperature stops rising.

In most cases, the recommended hot water temperature setting is 1200 F. This temperature is adequate for most uses. Hotter temperatures are not only wasteful, but also potentially hazardous, particularly in homes with young children . If you need a higher setting to "stretch" the water heater's capacity due to a large family, consider a larger tank when you replace your existing water heater.

With an electric water heater, the thermostats (usually two) are located behind cover plates on the side of the tank. Be sure to adjust both thermostats to the desired setting.

Caution! Before removing the cover plates, be sure to turn off the power at the circuit breaker to avoid the danger of electric shock.

Adjusting the temperature on a gas water heater is very simple, as the thermostat dial is located on the outside of the tank. You may need to experiment a bit to find the ideal setting for your needs.


Insulating Water Heater Tanks and Pipes

In the past, insulating water heaters was widely recommended, to reduce standby losses from the storage tank. Since the early 1990's, Department of Energy standards have required much higher levels of insulation between the tank and the exterior of the water heater. Because of this, the potential energy savings no longer justify the expense and trouble of installing an exterior insulation blanket.

You should, however, insulate any exposed hot water pipes, particularly in unheated areas. If the first several feet of cold pipe going into the tank feel warm to the touch, you should insulate them as well. Pre-formed foam sleeves are inexpensive, readily available and easy to install. Insulating hot water pipes will not only save energy, but may allow you to get hot water more quickly, as the water in the pipes won't cool off as quickly between uses.

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