How long to run water to avoid legionnaires?

Author: Fannie Bogan MD  |  Last update: Friday, October 17, 2025

Conduct routine flushing. Let your faucets and showers run for at least three minutes when they have been out of use for more than a week. Minimize exposure to splashing and mist generation, for example, by leaving the room while the water is running.

How often should you run water to prevent Legionella?

Stagnant water favours legionella growth. To reduce the risk you should remove dead legs/dead ends in pipe-work, flush out infrequently used outlets (including showerheads and taps) at least weekly and clean and de-scale shower heads and hoses at least quarterly.

How long do I let my shower run so I don't get legionnaires?

If your shower has not been used for a week or more, run water from both hot and cold supplies through the shower hose and showerhead for two minutes. To ensure no spray escapes from the showerhead, run it through a bucket of water or full bath.

How quickly do legionnaires develop in water?

How quickly legionella grows in pipes depends on the conditions, but in some instances, it can multiply to the extent that it becomes an issue within just two weeks. Often it can take longer, but once it takes hold, it can be difficult to get under control.

How long should you run an unused tap for?

If your home has been empty for over 7 days flush your toilet twice and run your taps and shower for five minutes to flush the hot and cold water systems.

How to prevent legionella

How long does it take to flush Legionella?

Whenever a property is to be left unused for a time, weekly flushing is a good way to reduce the chances of any problems cropping up. It is easy to do and requires only a small amount of time. Each tap and water outlet (including showers) should be opened and left to run through for at least five minutes.

How long to run water after not using for awhile?

Run each tap for 10 minutes or more. Make sure only one tap is running at a time. This will push out stagnant water and fill household pipes with fresh water. Your hot water tank should be drained before using any hot water in your house.

What kills Legionella in water?

One way to control Legionella growth in domestic hot water systems is to raise the water heater temperature to at least 70°C (158°F) for 24 hours and then flush each outlet (i.e., places where water comes out of the system, such as faucets and showers) for 20 minutes.

Can you tell if water has Legionella?

PCR is a fast and accurate way of detecting Legionella bacteria, often succeeding in detecting Legionella types when traditional methods fail; however, this method is traditionally more expensive, requires specialist equipment and results can be difficult to interpret.

What time of year is Legionnaires disease most likely?

More illness is usually found in the summer and early fall, but it can happen any time of year.

What are the first signs of Legionnaires' disease?

Legionnaires' disease, the pneumonic form, has an incubation period of 2 to 10 days (but up to 16 days has been recorded in some outbreaks). Initially, symptoms are fever, loss of appetite, headache, malaise and lethargy. Some patients may also have muscle pain, diarrhoea and confusion.

How often should you run water in an unused shower?

Here are some things to do if you have a bathroom that does not get used that often: The main thing is to run water in the sink, shower and flush the toilet at least once a week.

How common is Legionella at home?

Although it's possible to get Legionnaires' disease from home plumbing, most outbreaks have occurred in large buildings, perhaps because complex systems allow the bacteria to grow and spread more easily. Also, home and car air conditioning units don't use water for cooling.

How long should you run a shower that hasn't been used?

It is advisable to run any infrequently used showers or taps for about two minutes each week or until the hot and cold water are the same temperature as frequently used outlets. Make sure to leave the room to avoid potentially breathing in aerosols containing Legionella bacteria.

How to clean shower head legionella?

Soak in Vinegar: Fill a plastic bag with white vinegar and submerge the shower head in it. Secure the bag with a rubber band or string. Leave it to soak overnight or for at least 8 hours. Scrub Away Deposits: After soaking, remove the shower head from the vinegar.

How to test for legionella at home?

4 Simple Steps
  1. Step 1 - Order Testing Kit. Your Legionella Testing Kit will include water sample bottle(s), easy to follow instructions and a FREE return package.
  2. Step 2 - Fill Sample Bottle. Fill the water sample bottle(s) from your taps following the instructions.
  3. Step 3 - Return Delivery. ...
  4. Step 4 - Get your Results.

How quickly does Legionnaires develop in water?

How quickly can legionella develop in water systems? Many people are often shocked to discover just how quickly legionella can develop in a stagnant water system. In fact, given the right conditions, legionella can grow and become problematic in as little as two weeks.

What is the fatality rate for Legionnaires' disease?

The mortality rate of Legionnaires' disease varies between 5% and 15%, depending on the age and individual health status. People over the age of 50 are more at risk than younger people, as well as immunocompromised or persons with underlying illness. .

Will Legionella go away on its own?

Legionnaires' disease requires treatment with antibiotics. Most cases of this illness can be treated successfully. Identifying and treating the illness early can increase the chances of getting better. Healthy people usually get better after being sick with Legionnaires' disease, but they often need care in a hospital.

Can I shower in Legionella water?

Are some showers more of a Legionnaires' risk than others? That said, some showers are more likely to be at risk than others. For example, if you have a shower at home, you're unlikely to catch Legionnaires' disease from using it if it's regularly in use.

How often should taps be flushed for Legionella?

In most cases, water flushing should be carried out at least weekly to reduce the risk of Legionella and other bacterial growth. But in high-risk populations such as healthcare facilities and care homes, a risk assessment may indicate the need for more frequent flushing - i.e. twice weekly.

Can Legionella grow in chlorinated water?

The results indicate that legionellae are much more resistant to chlorine than are coliform bacteria. At 21 degrees C, pH 7.6, and 0.1 mg of free chlorine residual per liter, a 99% kill of L. pneumophila was achieved within 40 min, compared with less than 1 min for Escherichia coli.

How long to run tap water before drinking?

FLUSH YOUR SYSTEM. Let the water run from the tap before using it for drinking or cooking any time the water in a faucet has gone unused for more than six hours. The longer water resides in plumbing the more lead it may contain. Flushing the tap means running the cold water faucet for about 15-30 seconds.

What is the best practice for Legionella?

How can it be prevented? To ensure that water systems do not harbour dangerous levels of legionella bacteria: • Water systems and outlets must be maintained in good, physical condition and be kept clean. Water temperatures, between 20°C and 45°C, should be avoided.

How often should I flush unused toilets?

It's easy to let that toilet slip your mind, but it's important to give it a flush at least weekly to keep it flowing and free from sediment and unsightly toilet stains.

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