Operations & Maintenance: Domestic Hot Water
  • Lower water temperature. Domestic hot water should generally be provided at about 120 degrees F. If water in dwelling units is hotter than 120 degrees, the water temperature can be lowered to save energy. Individual hot water heaters should be set at 120 degrees, while in central systems, the temperature should be adjusted so that 120-degree water is provided to the dwelling units.
  • Repair all leaks. Maintenance staff should periodically inspect all apartments and repair leaky faucets. One leaking faucet can waste more than 1,000 gallons per year as well as 500,000 Btus necessary to heat it. In addition, staff should inspect the entire distribution system, valves, and pumps.
    Image: Insulate hot water pipes to conserve energy.
  • Insulate domestic hot water pipes. All domestic hot water circulation pipes should be insulated with one-half inch of insulation to reduce heat loss. Older domestic hot water heater tanks also should be insulated.
  • Turn off domestic hot water supply to areas that do not need it. Hot water supplies to areas such as utility rooms, boiler rooms, and other rooms should be turned off. Shut off should occur as near to the hot water heater as possible to reduce piping energy losses.
  • Reduce water pressure. In buildings where the water pressure is higher than necessary, a pressure regulator should be installed to reduce pressure to the minimum level required by local code. High water pressure results in high flow rates and water waste. It also can increase wear and tear on plumbing equipment and result in leaks.

    Photo: Sediment can be removed from tank-type water heaters through periodic flushing.
  • Flush tank-type water heaters. Tank-type water heaters (both gas and electric) should be flushed periodically to remove sediment. The accumulation of sediment on the bottom of the tank results in inefficient operation of the water heater. The water should be drained into a bucket until it runs clear.
  • Clean/adjust burners on gas and oil water heaters. Burners on gas- and oil-fired domestic hot water heaters should be cleaned and adjusted annually for combustion efficiency. The buildup of soot or other residue decreases combustion efficiency. If necessary, qualified stadd should adjust the flame in accordance with the manufacturer's manual.
  • Check electrodes on electric water heaters. Electrodes on electric water heaters should be checked for scale buildup. Removing scale buildup will increase heat transfer.

For more ways to reduce energy costs, see PHECC's Energy Conservation Measures.