Bacteria love warmth and water. And, in a domestic hot water system, they have plenty of both. This means that facilities managers and building operators for hotels, resorts, and apartment buildings need to take precautions to prevent bacterial growth in these hot water systems. Here are some insights from experienced commercial HVAC contractors:

Why Preventing Legionella Outbreaks is Essential

Legionella is a type of bacteria that is quick to infect people, as it is easily breathed in from water vapor. It causes Legionnaire’s disease, a severe form of pneumonia that is especially dangerous – and even lethal – to people who suffer from poor or under-developed lung health or who have a weakened immune system, such as the elderly, smokers, and babies. It can result in life-threatening complications such as respiratory failure, septic shock, and kidney failure.

A Legionella outbreak will not only put your clients, guests, tenants, and staff at risk, but it will also result in serious damage to the reputation of your establishment.

How to Prevent Legionella Outbreaks in Domestic Hot Water Systems

Fortunately, there are effective steps that you can take to prevent an outbreak. This includes:

  • Maintaining a Water Temperature of 140 Degrees F:
    These bacteria survive in a temperature range of between 68 and 122 degrees. However, they can also grow well between 77 and 108 degrees. So, keeping your water temperature well above this range will effectively eliminate it. It’s recommended that you go as high as 140 degrees because the bacteria can sometimes protect itself in water hotter than 122 degrees by using biological materials as a shield. This temperature must be maintained in all the hot water storage systems. But, it should be lowered for supply to guests and tenants to 120 degrees by using a high/low flow mixing valve. This is to ensure no one scalds themselves.
  • Eliminate Stagnation in the Hot Water System:
    Bacteria grow and thrive in water that is still and stagnant, including in the dead legs in your building’s piping. This also leads to scale and biological build-up, which bacteria can then utilize. All stagnant sections of your piping should be eliminated. Recirculation pumps can also be installed to keep the hot water moving continuously, eliminating stagnation and opportunities for scale build-up.
  • Maintain the Backflow Preventers:
    Backflow preventers should be maintained and checked regularly to ensure they are functioning properly. A problem with a backflow preventer can lead to cross-contamination of your water supply and the introduction of dangerous bacteria into the drinking water system. 
  • Domestic Hot Water System Maintenance:
    In addition, your entire domestic hot water system should be regularly serviced and maintained by professional HVAC contractors. This ensures that any issue can be rapidly detected and effectively repaired. They can also advise you on any upgrades your building can benefit from that will help to ensure a healthy and energy-efficient hot water supply, including state-of-the-art domestic hot water control systems.

Professional Installation, Maintenance, and Repair of Domestic Hot Water Systems in NJ

With over 30 years of experience in the commercial HVAC industry and a fleet of commercial crews that operate throughout New Jersey, Tri-Tech Energy is the ideal partner for your domestic hot water system’s installation, repair, and maintenance. For more information on our company or services, including our advanced domestic hot water control systems, please contact us today or visit our website at