Do I need a legionella certificate?

No. HSE says health and safety law does not require landlords to obtain or produce a legionella test certificate. What you need is the assessment itself and a record of it.

Does the water have to be tested?

Not usually. HSE says testing is not usually required for domestic hot and cold water systems. The assessment is about temperatures, how the water is stored and used, and what could let bacteria grow.

Can I do the assessment myself?

Yes, if you do it competently. HSE expects most landlords to be able to assess a simple domestic system themselves. DwellFlow guides you through it on your phone in thirty minutes to an hour, and the AI produces the documents.

How often does it need reviewing?

There is no fixed legal interval for a domestic property. Review it when the water system, its use or the occupants change, and periodically otherwise. Each DwellFlow assessment sets its own reassessment date from what the property is.

For landlords

Do landlords need a legionella risk assessment?

Yes. Every landlord in England and Wales has a legal duty to assess and control the risk of legionella in a rented home. For most houses and flats a simple assessment is enough, there is no such thing as a legionella certificate, and you can do it yourself.

What the law says

The duty is real, and it is yours.

Under the Health and Safety at Work Act and the COSHH regulations, a landlord is the person in control of the premises and responsible for its water system. HSE’s guidance for residential accommodation puts it plainly: landlords “have a legal duty to ensure that the risk of exposure of tenants to legionella is properly assessed and controlled.” It applies to a single let flat as much as to a portfolio.

What the law does not do is prescribe a form, a contractor or a piece of paper. It asks for the risk to be assessed by someone who knows what they are looking at, for anything found to be dealt with, and for a record.

Three things HSE says that agents often get wrong

No certificate. No routine test. A simple assessment can be enough.

“Health and safety law does not require landlords to obtain or produce a ‘legionella test certificate’.” If you have been told you need one before you can let, that is not what the law says.
Testing “is not usually required for domestic hot and cold water systems.” A water sample sent to a laboratory tells you what was in the water on one day. The assessment is about whether the system can let bacteria grow at all.
“A simple assessment may show there are no real risks and these are being properly managed so no further action is needed.” A combi boiler feeding a two-bed flat with no stored water is a short assessment. It still has to be done and written down.

All three lines are from HSE’s page on legionella and landlords’ responsibilities.

What a competent assessment contains

Their form says ☑ yes. A competent one says 15.0 °C beside a photograph of the tap.

The assessment is only as good as what it records. Whoever does it, for the property to be covered it should contain:

How the water is stored and heated. Combi, cylinder or tank; the size if there is one; whether stored hot water reaches 60 °C.
A temperature at every outlet. Hot at 50 °C within a minute of running; cold below 20 °C within two. A reading, not a tick.
The things bacteria like. Dead legs, little-used outlets, a shower head that is never cleaned, a tank with no lid, a property that stands empty.
Photographs beside each finding, so the record shows what was there on the day.
What to do about each finding, with the guidance clause it comes from, and a date.
The written scheme of control: what will be done to keep the risk down, and what the tenant needs to know.

Who does it

Most landlords can do it themselves. The question is whether it is competent.

HSE expects a landlord to be able to assess a simple domestic system. The difficulty was never the visit, it was knowing what to look at, what the numbers mean, and what to write. DwellFlow does that part: your phone asks the questions at the property, you take the readings and the photographs, and the AI does the write-up. Thirty minutes to an hour. Press submit and the assessment, a sheet for your tenant and the written scheme of control are produced.

If you use a letting agent, look at your agreement. The duty stays with you; HSE’s guidance says the management contract should clearly specify who is responsible for safety checks including legionella. An agent’s inspector can carry out the assessment on a visit they already make; the record still needs to reach your file.

How often

There is no fixed interval. There is a sensible one.

For a domestic property the law sets no calendar. The assessment should be reviewed when the water system changes, when its use changes, when the occupants change, and periodically in between. HSE suggests routine visits such as the annual gas check as the moment. Each DwellFlow assessment sets its own reassessment date from what the property is: a mains-fed house with nothing stored comes round far less often than one with a loft tank and a vented cylinder, and you are reminded when it falls due.

Questions landlords ask

Short answers.

Do landlords need a legionella risk assessment? Yes. Health and safety law requires landlords to assess and control the risk of exposure of tenants to legionella. For most domestic properties a simple assessment is enough.
Do I need a legionella certificate? No. HSE says health and safety law does not require landlords to obtain or produce a legionella test certificate. What you need is the assessment itself and a record of it.
Does the water have to be tested? Not usually. HSE says testing is not usually required for domestic hot and cold water systems. The assessment is about temperatures, how the water is stored and used, and what could let bacteria grow.
Can I do the assessment myself? Yes, if you do it competently. HSE expects most landlords to be able to assess a simple domestic system themselves. DwellFlow guides you through it on your phone in thirty minutes to an hour, and the AI produces the documents.
How often does it need reviewing? There is no fixed legal interval for a domestic property. Review it when the water system, its use or the occupants change, and periodically otherwise. Each DwellFlow assessment sets its own reassessment date from what the property is.
Does my letting agent do it for me? Only if your agreement says so. The duty stays with the landlord. HSE guidance says the management contract should clearly state who is responsible for safety checks including legionella.