What legionella checks does a landlord have to do?

The duty is to assess the risk from legionella and keep it under control. In practice that means a risk assessment, reviewed when things change, and the routine checks it sets out. For most homes those are temperatures, running any outlet that is not used, and clean shower heads.

How often should legionella checks be done?

The law sets no fixed interval. HSE names mandatory visits such as gas safety checks, and routine maintenance visits, as moments to inspect the water system. Flush every outlet before a new tenant moves in, and weekly while a property stands empty. The written scheme of control sets the rest for your property.

Is a legionella check the same as a legionella test?

No. A check is a temperature reading or a look at the system. A test sends a water sample to a laboratory, and HSE says testing is not usually required for domestic hot and cold water systems.

What equipment do I need?

A digital thermometer with a probe, to take the temperature of the running water. You do not need a testing kit.

Can my gas engineer or letting agent do the checks?

Yes. HSE names gas safety checks and routine maintenance visits as the times to inspect the water system, and anyone competent can carry out the assessment. HSE also says most landlords can assess the risk themselves.

For landlords

Legionella checks for landlords

Three different things get called a legionella check. The risk assessment is a survey of the water system, written down, and it is the landlord’s legal duty. The routine checks keep the risk low in between. A laboratory test is the third, and HSE says a home does not usually need one.

Written by Ken Millea, who ran a UK legionella consultancy for ten years.

Check, assessment or test

Three things with one name.

The risk assessment, sometimes called the inspection or the survey. A look at the whole hot and cold water system: how the water comes in, how it is stored and heated, a temperature at every outlet, what could let bacteria grow, and what will be done about it. Written down, and reviewed when something changes. What a risk assessment is.
The routine checks. Short checks between assessments that show the system is still under control. The written scheme of control lists them for each property.
The laboratory test. A water sample sent away for analysis. HSE says it “is not usually required for domestic hot and cold water systems, and is only needed in very specific circumstances”. When a test is needed.

The routine checks

Hot water hot, cold water cold, and keep it moving.

HSE: “For most domestic hot and cold water systems, temperature is the most reliable way of ensuring the risk of exposure to legionella bacteria is minimised – keep the hot water hot, cold water cold and keep it moving.”

Temperatures. Hot water stored at 60 °C; hot at the tap reaching 50 °C within a minute; cold below 20 °C within two minutes. A probe thermometer in the running water, not a hand under the tap.
Flushing. HSE lists “flushing out the system prior to letting the property”. While a property stands empty, run every outlet weekly, or drain the system if it will be empty for a long time. Empty properties.
Shower heads. A shower makes a spray that can be breathed in, and scale gives bacteria somewhere to settle. HSE says tenants should be advised to “regularly clean and disinfect showerheads”.
Anything that has changed. A new bathroom, an outlet taken out, pipework that no longer goes anywhere. HSE lists “make sure any redundant pipework identified is removed”, and a change to the system is also a reason to review the assessment.
Stored water, where there is any. HSE: “ensure the cold water tanks, where fitted, have a tight-fitting lid”.

When to check

On visits you already make.

The law sets no fixed interval for the checks or for the assessment. HSE says “the law does not prescribe that the risk assessment be reviewed on an annual or biennial basis”, and that checks can be made “during mandatory visits such as gas safety checks or routine maintenance visits”.

So the natural moments are the annual gas safety check, a routine inspection, and every change of tenant. The tenant has a part too: HSE says tenants should be told the control measures to keep up, such as not adjusting the temperature setting on the hot water cylinder, cleaning shower heads, and telling you if the hot water is not heating properly. All of it is on HSE’s page on legionella and landlords’ responsibilities.

Where DwellFlow fits

The assessment sets the checks. The AI writes both down.

DwellFlow walks whoever is at the property through the survey on a phone: the readings, the photographs, the questions. The AI then writes the risk assessment, a sheet for the tenant and the written scheme of control, which lists the routine checks for that property and sets the date for the review.

£9.99 ex VAT a property. Thirty minutes to an hour at the property, depending on the size and type of the water system, and a digital thermometer with a probe is the only thing to buy. If you would rather somebody else did it, we can send a surveyor.

Questions landlords ask

Short answers.

What legionella checks does a landlord have to do? The duty is to assess the risk from legionella and keep it under control. In practice that means a risk assessment, reviewed when things change, and the routine checks it sets out. For most homes those are temperatures, running any outlet that is not used, and clean shower heads.
How often should legionella checks be done? The law sets no fixed interval. HSE names mandatory visits such as gas safety checks, and routine maintenance visits, as moments to inspect the water system. Flush every outlet before a new tenant moves in, and weekly while a property stands empty. The written scheme of control sets the rest for your property.
Is a legionella check the same as a legionella test? No. A check is a temperature reading or a look at the system. A test sends a water sample to a laboratory, and HSE says testing is not usually required for domestic hot and cold water systems.
What equipment do I need? A digital thermometer with a probe, to take the temperature of the running water. You do not need a testing kit.
Can my gas engineer or letting agent do the checks? Yes. HSE names gas safety checks and routine maintenance visits as the times to inspect the water system, and anyone competent can carry out the assessment. HSE also says most landlords can assess the risk themselves.