All residential properties which are rented out must now have a risk assessment undertaken to determine the risk of Legionella, which then allows landlords to implement a suitable control scheme.
Legionella are bacteria that are common in natural (rivers and lakes etc) and artificial water systems, eg hot and cold water systems (storage tanks, pipework, taps and showers).
We usually associate Legionella with larger water systems, eg in factories, hotels, hospitals and museums, and cooling towers, but they can also live in smaller water supply systems used in homes and other residential accommodation.
As a landlord, under health and safety law, you have a duty to take suitable precautions to prevent or control the risk of exposure to Legionella.
A risk assessment is your responsibility and will help you to establish any potential risks and implement measures to either eliminate or control risks.