Legionnaires' disease
Legionnaires' Disease can be fatal and is caused by the inhalation of small droplets of contaminated water containing Legionella bacteria. Where a property or bedsit room with its own en-suite has not been used for a long time, such as during lockdown, or when the tenant has stayed elsewhere or you have not been able to move a tenant in, the period of time that water has been standing in pipework means that Legionella bacteria may multiply. When water in these pipes is first used, airborne droplets of water have a potential risk of containing Legionella, particularly from shower heads.
As a general principle, outlets on hot and cold water systems should be used at least once a week to maintain a degree of water flow and minimise the chances of stagnation. To manage the risks during non-occupancy, consideration should be given to implementing a suitable flushing regime or other measures such as draining the system if it is to remain vacant for long periods. Any hot water cylinders (calorifiers) should be set to ensure water is stored at no lower than 60°C. Before opening up or re-letting your property after lockdown, you must consider the risks presented by Legionella, especially if the water systems have not been proactively run during this period or not drained down, and must take appropriate action to minimise the risk of Legionnaires Disease, for which you may need specialist help and advice. Advice and guidance can be found on the HSE webpage.