All hot water delivery systems in any commercial or institutional site need to be given detailed consideration to the potential of Legionella proliferation during the shutdown. This will necessitate that certain procedures and measures are carried out before the system can be made ‘live’ and function efficiently.
ACOP L8 guidelines, produced and published by the Health & Safety executive, lists the details and necessary procedures to ensure system cleanliness. According to ACOP L8, continuous flow direct to outlet systems are seen as low risk for Legionella, due to it allowing for a full turn-over of water volume, no stored water and accurate temperature control.
Start with an inspection: the first and most important point of a comprehensive and detailed inspection of the appliances is to ensure they can operate to maximum efficiency, especially if there is no record of what procedures were taken when the system was shut down.
So, to bring a continuous flow hot water heating system back to active service please note the following procedures and considerations:
Other modes of hot water delivery systems will have their own sets of procedures. Best advice to site managers and maintenance personnel is to ensure they obtain specific sets of information and procedures for their particular system. This may be time consuming, but it is important to check for possible Legionella given that the lockdown has been here for several weeks – and it has been an ideal time for bacteria proliferation.
Or sites may want to consider that it is the perfect opportunity to switch to a continuous flow system of hot water delivery. This will ensure a limitless supply of hot water is available, provided there is no interruption to gas and water supplies. Continuous flow is acknowledged as more technologically advanced, more efficient, more cost effective with less front-end costs and better Whole of Life economics.