Water safety (legionella)

Legionnaires' disease is an uncommon but potentially fatal form of pneumonia. It is caused by breathing in small droplets of water from contaminated sources containing Legionella bacteria.

Everyone is susceptible to infection, but some people are at higher risk. These include:

  • People over 45 years of age
  • Smokers and heavy drinkers
  • People suffering with respiratory or kidney disease, or anyone with an impaired immune system

Legionella in the home

All hot and cold water systems in residential properties are a potential source for Legionella bacteria growth.

The main areas of risk are where the bacteria can multiply and increase to dangerous levels and then spread, such as in spray from showers and taps, or in dishwasher and washing machine pipes.

Legionella can multiply where the water temperature is between 20°C and 45°C, and where water is stagnating, any sludge, rust, or scale can settle in one place giving the bacteria the nutrients to grow. Fouled or scaled shower heads or taps can also provide nutrients.

What you can do

Simple and easy precautions can keep your home's water supply clean and healthy.

The 4 key steps are:

  • Keep your hot water hot – but beware of scalding
  • Keep your cold water cold
  • Keep your water circulated
  • Keep shower heads and taps clean and in a scale free condition
  • If you have any outlets (taps, showers, or toilets) that you don’t use every week, these need to be flushed weekly

Inform us if the boiler or hot water cylinder are not working correctly. Hot water should be at a temperature of at least 50℃ at the tap within one minute of flushing.

Stored hot water should be set so that the cylinder achieves 60℃ degrees in temperature for a minimum of an hour a day. You should not interfere with the settings of your boiler or hot water system. Warning: beware of scalding from hot water

Tell us if cold water is running warmer after 2 minutes of flushing. Cold water should not be above 20℃ degrees.

Tell us if you have any consistent issues with debris or discolouration of hot or cold water.

If you have a shower

If your shower is only used occasionally, it should be flushed through for at least 2 minutes once a week on the hottest setting.

It is preferable to have the shower head removed from the hose to reduce the aerosol droplet production, but if this is not possible or practical, you can place a plastic bag over the shower till full then slowly pour away.

Shower heads should be cleaned and descaled at least every 3 months but more often if required. A store-bought disinfection cleaner is more than adequate for this job.

Holidays away from home

When a property has been left vacant for more than a week it’s recommended that all taps, showers, and outlets are flushed through thoroughly.

All taps should be run slowly for 1 minute to avoid creating any aerosol droplets and after the minute slowly fully opened and left to run for 4 more minutes. You should be careful at this stage not to let water overflow from sinks or basins - adjust how much the tap is opened if required.

Flush your toilet twice with the lid down before using.