What can be done to prevent Legionella bacteria from proliferating in water heaters and their related systems? 

“While some manufacturers are starting to market appliance add-ons and other means to manage Legionella bacteria, water temperature along with following any recommended cleaning remains the best way to address this concern. Make sure that you consult with your professional installer and water heating product manufacturer for water heating recommendations. You will have to balance system temperatures that will prevent bacterial growth and then hot water output to avoid scalding hazards to end users.”

— Dustin Bowerman, senior director of field services, Bradford White Corporation    

“Legionella is an issue with water quality before it enters the water heater. Water should be treated before use to prevent contamination.”

— Mike Henry, Trainer III, Rheem   

“Tankless technology can be a valuable cornerstone to any building’s water management plan to mitigate Legionella. Rinnai’s commercial tankless units eliminate the need for large storage tanks and create hot water on demand and at inhospitable temperatures for Legionella.”

— David Frederico, senior director of marketing, Rinnai   

“With around 6,000 reported cases of Legionnaires’ disease each year in the United States, reducing the risk of Legionella is critical for every facility, especially healthcare properties.

Simply swapping out tank-style water heaters for tankless ones will dramatically reduce the potential for Legionella growth due to three primary reasons:

1. Stagnant, stored water presents the ideal conditions for bacteria to thrive in. It also speeds up the accumulation of impurities like sediments and biofilm which hastens contamination. Reducing or eliminating these impurities is key to reducing Legionella risks.
2. Tankless units maintain a consistent output water temperature without any additional controls in place, eliminating mechanical points of failure found in mixing valves. Such consistency eliminates the need to stratify water. Water stratification results in pockets of attractive temperatures for Legionella. Creating temperatures that are inhospitable to Legionella is key to mitigating its risk.
3. Finally, tankless units use advanced flow control, which keeps the water moving rather than storing it in stagnant tanks. Legionella cannot thrive in moving water.

Earlier this year, Intellihot introduced the Legionator, a point-of-use tankless water heater that generates Ozone to control bacterial growth in pipes and point-of-use water fixtures.”

— Amy Turner, director of marketing, Intellihot   

Jeff Wardon, Jr. is the assistant editor for the facilities market.