As a homeowner, it's your responsibility to ensure that your appliances aren't posing a threat to the well-being of you and your household members. When it comes to your water heater, ensuring safe operation isn't very easy. Not only do you have to ensure that your relief valve is releasing excess pressure, but you must also ensure that your water tank doesn't serve as a breeding ground for Legionella bacteria.
Legionella is a genus of bacteria that, when inhaled or ingested, is capable of causing Legionnaire's disease. Legionnaire's disease causes symptoms such as excessive coughing, breathing difficulty, muscle pain, and headaches. Legionnaire's disease is commonly mistaken for pneumonia due to similar symptoms.
People with existing health issues (specifically respiratory problems) are likely to experience more intense symptoms of Legionnaire's disease than healthy people. Severe complications of Legionnaire's disease can include lung failure and even death. However, even healthy individuals who contract Legionnaire's disease should seek treatment at a hospital. In most cases, antibiotics are required to kill Legionella bacteria.
Legionella bacteria enter your water tank through your water supply. The bacteria are capable of sustaining themselves inside your water tank as long as your water temperature is between 95-115 degrees Fahrenheit.
You can mitigate Legionella growth by keeping your water heater's thermostat above 122 degrees Fahrenheit. However, in order to kill Legionella bacteria within a reasonable amount of time, your thermostat must be set to 131 degrees or higher.
However, increased water temperature can result in scalding--especially for young or elderly members of your household. To keep the water stored inside your tank at a safe temperature and prevent scalding, you'll need to install or calibrate a mixer valve to decrease the temperature of your hot water supply as it travels throughout your plumbing system.
Even if you set your thermostat to 122 degrees or 131 degrees Fahrenheit, there's still a possibility that Legionella bacteria can live inside your water tank if your thermostat is malfunctioning or improperly calibrated.
Additionally, depending on the design of your thermostat, your water heater won't necessarily keep your water tank at the temperature set on your thermostat. To save unnecessary fuel or electricity costs, some water heaters are designed to let the water temperature fall several degrees beneath the set temperature before the heating components are activated.
To determine whether or not your thermostat will experience these complications, have a professional plumber or appliance technician calibrate your thermostat and measure the temperature of your tank's standing water. Additionally, your water heater's owner manual may provide insight for programmed temperature fluctuations.
Heating Component Inspection
Your heating components (either a burner assembly or heating elements) will only be able to heat your water tank to the temperature specified by your thermostat if they remain in good condition. However, minerals inside your tank, condensation in your combustion chamber, and other issues such as electrical failures can affect the performance of your heating components.
To ensure that your heating components are kept in good condition, you'll need to inspect them at regular intervals. If you have a gas water heater that has a dirty or rusted burner assembly, you'll need to clean it and replace any rusted components to ensure reliable operation. If you have an electric water heater, then periodically testing the elements for the proper electrical load with a meter and replacing them when they become burnt out or destroyed by mineral scale will keep them operating properly.
Preventing Legionella bacteria from growing inside of your water tank requires several steps. If you don't adjust your water temperature, calibrate your thermostat, and ensure that your heating components are operating properly, then your water tank may still be a suitable environment for Legionella growth. If you're incapable of taking these precautionary steps on your own, then hire an appliance technician or plumber to perform the required maintenance for you.