What counts as a little-used outlet?
HSG274 treats any outlet used less than once a week as little used. Typical examples are spare bathrooms, en-suites in empty rooms, cleaners' sinks, outside taps and showers in unused changing rooms.
How often to flush
Flush little-used outlets at least weekly. Where a building or room has been empty for longer, flush before it is used again. If an outlet is no longer needed at all, removing it and the pipework that feeds it is better than flushing forever.
How long to run the tap
Run each outlet until the water reaches its normal temperature, hot running hot and cold running cold, rather than for a fixed time. In practice this is often two minutes or more, longer on long pipe runs. Your risk assessment may set a specific time.
Doing it safely
- Open taps slowly to limit splashing
- Remove or point shower heads into the tray or bath and run gently to avoid spray
- Close toilet lids before flushing
- Start nearest the water heater or tank and work outwards
Record it
Write down the date, outlets flushed and who did it. Our free flushing record sheet makes this easy.
Frequently asked questions
How long should you run taps for legionella?
Run each tap until the water reaches its normal hot or cold temperature. This is often two minutes or more. Your risk assessment may give a set time.
Do toilets need flushing for legionella?
Little-used toilets should be flushed as part of the weekly routine, with the lid closed.
Do self-flushing taps remove the need to flush?
Automatic flushing devices can help, but they must be set up correctly, checked and recorded like any other control.
Disclaimer: This guide is general information about UK requirements and is not legal advice. Always check the current legislation and guidance for your premises.