Routine control measures
Legionella checks and flushing
The risk assessment tells you what to do. These checks are the doing. HSE's advice comes down to three things: keep hot water hot, keep cold water cold, and keep it moving.
Last reviewed October 2026 against HSE guidance.
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Routine checks at a glance
| Check | HSE's guidance | Who usually does it |
|---|---|---|
| Flush rarely used outlets | Use outlets at least once a week to keep water moving | Tenant, caretaker or staff |
| Hot water at sentinel outlets | Monthly: at least 50°C within 1 minute | Responsible person or contractor |
| Cold water at sentinel outlets | Monthly: below 20°C after 2 minutes | Responsible person or contractor |
| Hot water cylinder | Outgoing water at least 60°C | Responsible person or contractor |
| Cold water storage tank temperature | Every 6 months, at the ball valve outlet | Responsible person or contractor |
| Cold water storage tank condition | At least annually: clean, with a tight-fitting lid | Responsible person or contractor |
| Showerheads | Clean and disinfect regularly | Tenant or cleaner |
Frequencies are from HSE's guidance for hot and cold water systems in workplaces and smaller buildings. For a single rental property, HSE says simple, proportionate measures are enough.
How to flush a water system
Flushing replaces water that has been standing in pipes with fresh water from the mains or the cylinder.
- Start with the outlet nearest to where water enters the property and work to the furthest.
- Run each tap for several minutes, until the cold runs cold and the hot runs hot.
- Run showers with the head lowered into the tray or a bucket, or covered, so you do not breathe in spray.
- Flush toilets with the lid down.
- Include outside taps, utility sinks and any outlet that is rarely used.
- Note the date.
HSE's advice to landlords is to flush out the system before letting the property.
Empty properties
HSE says it is important that water is not allowed to stagnate, so properties left vacant for extended periods need careful management. As a general principle, outlets should be used at least once a week.
- Short voids: flush every outlet weekly and again just before the new tenant moves in.
- Long voids: HSE suggests a suitable flushing regime or other measures such as draining the system.
- Student and holiday lets: plan flushing for the weeks the property is empty, and record it.
Showerheads, tanks and dead legs
- Showerheads and hoses. Showers create the fine spray that carries legionella. HSE says tenants should be advised to regularly clean and disinfect showerheads. Remove the head, descale it, and soak it in a suitable disinfectant.
- Cold water tanks. Check that the lid fits tightly, that the tank is insulated, and that there is no debris, rust or sludge. HSE advises keeping stored water to about one day's use.
- Dead legs and redundant pipework. A capped pipe or an outlet nobody uses holds stagnant water. HSE's advice is to make sure any redundant pipework identified is removed.
Keeping records
Write down what you checked, the readings and the date. For employers, keeping records is one of the five legal duties. For landlords it is the simplest way to show the property was looked after.
The free template includes a temperature log and a flushing record you can print and keep with the property file.
Questions people ask
How often should taps be flushed for legionella?
HSE's general principle is that outlets on hot and cold water systems should be used at least once a week. Outlets in daily use do not need separate flushing.
How long should you run taps to flush for legionella?
Run each outlet for several minutes, until the cold water runs cold and the hot water runs hot. That shows fresh water has replaced what was standing in the pipe.
Do landlords have to do monthly temperature checks?
HSE's monthly sentinel checks are written for workplaces and larger buildings. For a domestic rental, HSE asks for simple, proportionate control measures and suggests checks can be made during routine visits.
How do you clean a showerhead for legionella?
Unscrew the head, remove scale, soak the head and hose in a suitable disinfectant following the product instructions, rinse and refit. HSE says tenants should be advised to do this regularly.
Sources
- HSE: Hot and cold water systems, things to consider
- HSE: Legionella and landlords' responsibilities
- HSE: Hot and cold water systems
- HSE: Legionnaires' disease, what you must do
Checked against these sources in October 2026. This page is general information, not legal advice.
Start with the free template
An editable Word template for a simple rental property, based on the points HSE asks landlords to consider.
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