How To Prevent Legionnaires’ Disease in Rental Properties

Legionnaires’ disease is a serious illness which spreads when bacteria get into contaminated water tanks and pipes.

When water contaminated with legionella bacteria is inhaled into the lungs, the bacteria are consumed by a type of white blood cell called microphages, inside which they multiply until the blood cell dies. Causing flu-like symptoms, shortness of breath and chest pains, around 30% of those infected die from the disease – increasing to one in two if symptoms are untreated.

Landlords should take the threat of Legionnaire’s disease seriously, as it is your responsibility to ensure the safety of your tenants by keeping the home hazard-free.

What would make my property high risk?

Though all manmade water systems could technically host the bacteria, most residential hot and cold water systems are considered to be ‘low risk’ owing to regular daily water usage and turnover. Usually cold water will come directly from a mains supply, and hot water is fed from instantaneous heaters or low volume water heaters.

However, if water is allowed to stagnate the risk is significantly higher, for example if a building gets its cold water supply from stored water tanks, or if a property is left unoccupied for a long period of time. As a general rule, outlets on hot and cold water systems should be used at least once a week.

What can I do?

To ensure the risk of bacteria remains low in domestic systems

  • Ensure hot water stays hot and cold water stays cold – and keep it all moving
  • Before letting out a property, flush out the system
  • Avoid debris getting into the system by keeping a tight lid on water tanks
  • Set control parameters, e.g. set the hot water cylinder to ensure water is stored at 60°C
  • Inform tenants not to change these control measures, and to regularly clean showerheads and inform the landlord if the hot water is not heating properly
  • Identify and remove any redundant pipe-work

What are the consequences?

Landlords found to be in breach of their duties can face prosecution by the Health & Safety Executive (HSE), with a maximum £20,000 fine and up to two years in jail. In addition, if a tenant contracts Legionnaires’ disease they may bring a civil claim against their landlord.