Legionella are bacteria that are common in natural and artificial water systems such as hot and cold water systems. Legionella is usually associated with larger water systems in factories, hotels, etc. but they can also live in smaller water supply systems used in homes.
Legionella bacteria can multiply in hot or cold water systems and storage tanks in residential properties, and then be spread for example in spray from showers and taps. Legionella can survive in low temperatures, but they can thrive at temperatures between 20ºC and 45ºC; high temperatures of 60ºC and over will kill them.
The risk of legionella causing illness in small domestic properties is exceedingly low. Possibly the biggest risk is when the property has been empty for more than a week or so.
If you are returning from more than a week away from home or are moving into the property it’s good practice to:
- Run the taps and flush any shower heads with hot water for around one minute after a period of non-use. To flush the shower head remove it from its holder before switching on the shower and then hold down over drain as close as possible to lessen risk of inhaling sprayed droplets.
- Clean and de-scale shower heads every three to six months.
- Flush toilets twice to circulate water through the system.