• Benefits accrue from lowering a hot-water heater's temperature by 10 degrees.water facility image by Horticulture from Fotolia.com
  
  The hot-water tanks found in most houses and mobile homes have a temperature control dial, which allows owners to increase or decrease the temperature of the water. Often the temperature of a hot-water tank is set higher than necessary, though the homeowner may not realize it. A typical water heater comes from the factory set at 140 degrees Fahrenheit. It is possible to lower the temperature by 10 degrees, but hot-water heaters should retain a minimum temperature of 120 degrees to avoid Legionellosis bacteria contamination.
  
  

Energy Costs

• Lowering the temperature of a hot-water heater by 10 degrees will result in a 3 percent to 5 percent reduction in energy costs, according to the U.S. Department of Energy. Savings are dependent on several factors, including whether the heater is gas or electric and the regional price of energy. For example, using the minimum percentage provided by the Department of Energy, a household that consumes $300 in energy every month before lowering the temperature of its hot-water heater will experience a minimum savings of $108 per year for every 10 degrees in temperature reduction.
  
  

Lifespan

• All water tanks and heaters experience a gradual build-up of minerals, which eventually require the hot-water tank to be replaced. Lowering the thermostat on a hot-water tank by 10 degrees will slow the rate of mineral buildup and result in a longer lifespan. In addition, a higher temperature in water tanks results in faster corrosion of the copper, steel, or aluminum that the tank is made out of, as well as the valves and pipes that connect to the tank. Lowering the temperature will also lengthen the lifespan of the sacrificial anode, a magnesium or aluminum tube that is designed to corrode instead of the metals of the hot-water heater.
  
  

Safety

• Some hot-water tank manufacturers ship water heaters with the dials preset to 140 degrees Fahrenheit, which is high enough to cause third-degree burns to both humans and animals. Lowering the temperature by 10 degrees will lower the risk of severe burns and increase the safety for children who have access to faucets.