Lower Hot Water Heater Temperature Reduces Scald Risk but Increases Risk of Bacterial Growth Most homes and apartments have water heaters set at 140°F or above; a severe burn can occur in 5 seconds at 140º F or in 1 second at 150º F. But lower water heater temperatures can increase bacterial growth. For example, 120°F has been the standard recommended water heater temperature for reducing hot water scalding risk. This lower temperature, however, can increase health risks, as bacteria can thrive at temperatures below 140º F, especially in electric heaters. Older adults with weakened immune systems are at increased risk for Legionella bacteria (which causes pneumonia) when water heater temperatures are reduced. As Legionnaire disease is primarily spread through droplets, the shower and bath area are key risk areas. Many factors affect how much Legionella will multiply and whether they create a health risk, such as: Water temperature and mineral content Water heater type or design Health of people in the household

Anti-Scald Valves Reduce Scald Risk and Legionnaire's Disease To reduce both the risk of Legionnaire's disease and scalds, many experts recommend keeping the hot water heater set at higher temperatures (140°F+) and delivering safer, temperate water (110° – 120°) at the tap through the use of anti-scald valves. A severe burn can still occur at 120°F, but it takes 5 minutes, allowing the person and caregiver more time to react. There are two basic types of anti-scald valves: DIY screw-on valves that reduce scalding water to a trickle at the tap Plumber Installed valves that adjust the water temperature in the pipe before it flows from the tap: Single faucets Specific rooms Entire house

Trade Name Temperature Activated Flow Reduction Valves (TAFR) Description These DIY anti-scald products are available as either separate valves that you screw onto existing faucets and showerheads or as replacement fixtures (tub spouts, showerheads, or hand held shower heads) with integral anti-scald valves. Screw On Anti-Scald Valve for Faucet or Showerhead Photo courtesy of Anti Scald, Inc. Handheld Shower Head with Integral Anti-Scald Device Photo courtesy of American Valve, Inc Shower Head with Integral Anti-Scald Device Photo courtesy of American Valve Inc. Tub Spout with Integral Anti-Scald Device Photo courtesy of American Valve, Inc. How They Work An internal metal alloy expands when the water temperature reaches 115 - 120º, reducing the water flow to a trickle. For the water to flow again, the hot water knob must be turned off while the cold water knob is kept on, and then the water must be remixed again to a safe temperature. PROS Especially helpful for apartment dwellers who don't have access to the hot water heater or pipes in the wall. Inexpensive. Fairly easy to install, with the exception of the tub spout, as the old spout may be difficult to remove. The temperature in the water heater can be maintained at higher temperatures to avoid bacterial risk. CONS Maximum hot water temperature is pre-set by manufacturer Device may turn water off during an activity (e.g., dish washing) at temperatures user finds acceptable Hot and cold water must be manually remixed after the device reduces the flow to a trickle or the water will not flow May malfunction over time due to local water conditions Special Note: Because persons with dementia may be unable to operate the faucet with the anti-scald valve installed, it may be best used with a live-in caregiver, given that the hot and cold water must be properly mixed or the water will not flow. Devices should be checked often to make sure they're working properly.

Trade Name Thermostatic Mixing Valves How They Work Photo courtesy of Watts Regulator Company These point-of-use "thermostatic mixing" valves are installed directly on the pipes at sinks and bathing areas, mixing cool and hot water in  the pipe before the water flows out of the faucet. Some models allow the consumer to adjust the water temperature after installation, but offer a safety cap to protect against unwanted meddling; other models require a plumber to do the adjustment. PROS These are excellent for individuals living alone (no need to remix hot and cold water as in the TARFS shut-off model) and for apartment dwellers without access to the water heater. The valve mixes cold and hot water to a safe pre-set maximum temperature before it flows out of the faucet. The temperature in the water heater can be maintained at higher temperatures to avoid bacterial risk. TIP You'll need to tell plumber the maximum hot water temperature you'd like at the tap. Consider 110F, the maximum temperature allowed in nursing homes. CONS Must be installed by licensed technician Additional expense (valves $75+ plus approximately ½ to 1 hour of labor)

Trade Names Mixing Valves or Tempering Valves How They Work Photo Courtesy of Honeywell These valves are installed outside the hot water tank and mix cool and hot water so the water can be delivered at a safer temperatures (110° to 120° degrees F) to individual faucets and shower heads, for one room only or the whole house (except for the dishwasher and washing machine which can be maintained at higher temperatures). The mixing valves come in a variety of models for different plumbing systems, water heaters, and house sizes. Depending on the size of your home, you may need extra valves at individual taps, especially in the bathing area. Consult a plumber for more information. PROS Excellent anti-scald control for individuals living in their own home Cold and hot water mixed to a safe pre-set maximum temperature before it flows out of the faucet The temperature in the water heater can be maintained at higher temperatures to avoid bacterial risk TIP You'll need to tell the plumber the maximum hot water temperature at the tap. Consider 110° F, the maximum temperature allowed in nursing homes. CONS Must be installed by licensed technician Additional expense (cost of valve plus labor)

The standard recommended water heater temperature for reducing scalding risk has been 120°F. Be aware that individuals with compromised health and those undergoing chemotherapy are at increased risk for Legionnaires Disease with water stored at 120°F. It's important that each caregiver assess their care receiver's scald risk and health safety. Whenever possible, it's recommended that you use anti-scald valves for scald protection.

Residential water heater temperature: 49 or 60 degrees Celsius (120 or 140° F) from the Canadian Journal of Infectious Diseases and Medical Microbiology January/February 2004, Volume 15, Number 1 http://www.pulsus.com/infdis/15_01/leve_ed.htm Tap Water FAQ's, Safe Kids Canada http://www.sickkids.ca/skcforparents/section.asp?s=Topics&sID=10774&ss=Scalds+and+Burns&ssID=11337&sss=Tap+Water+FAQ's&sssID=13717 Burn Center Launches Anti-Scald Campaign http://www.umich.edu/~urecord/0304/Apr19_04/18.shtml Hot Water Safety Position Statement http://www.acicr.ualberta.ca/documents/HotWater2003PositionStatement.pdf Thermostatic Mixing Valves: Summary Bulletin http://www.homemods.info/files/TmvSummBullNov04_0.pdf Legionellosis: Legionnaires' Disease (LD) and Pontiac Fever http://www.cdc.gov/legionella/patient_facts.htm

American Valve, Inc. DIY replacement tub spouts, showerheads, or hand held showerheads with integral anti-scald valves. Anti-Scald Inc. DIY valves that you screw onto existing faucets and showerheads. Honeywell International, Inc. Valves for individual faucets, specific rooms, or whole house. Watts Water Technologies Valves for individual faucets, specific rooms, or whole house.