Does it have to be reviewed every two years?

No. The two-year figure in the code of practice is about records: keep the assessment while it is current and for at least two years afterwards. It is not a review interval, though it is often quoted as one.

Does it have to be reviewed every year?

No. HSE says the law does not prescribe an annual review. A routine visit such as the annual gas check is a sensible moment to look at it again, but nothing in law sets a calendar.

Does a new tenant mean a new assessment?

A change of occupants is a reason to look at the assessment again, not automatically to redo it. If the water system and its use are unchanged, confirm it and date the review. If the property stood empty, if the new household includes someone more susceptible, or if anything about the system changed, reassess.

What if nothing has changed?

Review it anyway, periodically. The code says the record is a living document. Read it through, check the temperatures still hold, write the date on it.

For landlords and agents

How often does a legionella risk assessment need reviewing?

There is no fixed legal interval for a rented home. HSE says the law does not prescribe an annual or two-yearly review. The code of practice says review it regularly and whenever there is reason to suspect it is no longer valid, and lists what counts. The two-year figure people quote is about keeping records, not reviewing.

What the code says

“Regularly, and specifically whenever there is reason to suspect it is no longer valid.”

The Approved Code of Practice, L8, calls the record of the assessment “a living document that must be reviewed to ensure it remains up-to-date”, and says to arrange a review regularly and specifically whenever there is reason to suspect it is no longer valid. It gives six examples of what that reason might be:

changes to the water system or its use
changes to the use of the building in which the water system is installed
the availability of new information about risks or control measures
the results of checks indicating that control measures are no longer effective
changes to key personnel
a case of legionnaires’ disease associated with the system

HSE’s guidance for landlords puts the same thing in one line: “The law does not prescribe that the risk assessment be reviewed on an annual or biennial basis. It is important to review the assessment periodically in case anything changes.” It is on the page on legionella and landlords’ responsibilities.

Where “every two years” comes from

Two years is how long to keep the record, not how often to redo it.

The same code says records of the assessment should be kept “throughout the period they are current and for at least two years afterwards”, and records of any monitoring or checks for at least five years. That is the two years. Somewhere along the way it became a review interval, and a repeat visit every two years is a convenient thing for an assessor to sell. Nothing in the current law or code requires it.

In a rented home

What “reason to suspect” looks like on a Tuesday.

The system changed. A combi replaced the cylinder, or the other way round. A loft tank was removed or replaced. An extension added a bathroom. A shower went in.
The use changed. The property stood empty for a month. A single tenant became a household of five. A room became a let in its own right.
The occupants changed. Someone in the new household is over 45, a smoker, or living with a lung condition or a weakened immune system, the groups HSE says are most at risk.
A check failed. The hot water is not reaching temperature. The cold is running warm in summer. The tenant reports the shower spluttering.
Nothing changed, but time passed. A routine visit, the annual gas check above all, is the natural moment to read the assessment through, check the temperatures still hold, and date it.

How DwellFlow sets the date

From what the building is, not from a calendar.

Every DwellFlow assessment prints its own review date, set from the property’s inherent risk: how the water is stored and heated, how many outlets there are, who lives there. A mains-fed flat with a combi boiler and no stored water comes round far less often than a house with a loft tank and a vented cylinder. The date is between six months and five years out, and you are emailed when it falls due. A review is a new assessment at the same price; a correction within fourteen days of the survey is free.

Questions landlords ask

Short answers.

How often does a legionella risk assessment need reviewing? There is no fixed legal interval for a rented home. HSE says the law does not prescribe an annual or two-yearly review. Review it regularly, and specifically whenever there is reason to suspect it is no longer valid: a change to the water system, its use or the occupants, or a check that shows a control is not working.
Does it have to be reviewed every two years? No. The two-year figure in the code of practice is about records: keep the assessment while it is current and for at least two years afterwards. It is not a review interval, though it is often quoted as one.
Does it have to be reviewed every year? No. HSE says the law does not prescribe an annual review. A routine visit such as the annual gas check is a sensible moment to look at it again, but nothing in law sets a calendar.
Does a new tenant mean a new assessment? A change of occupants is a reason to look at the assessment again, not automatically to redo it. If the water system and its use are unchanged, confirm it and date the review. If the property stood empty, if the new household includes someone more susceptible, or if anything about the system changed, reassess.
What if nothing has changed? Review it anyway, periodically. The code says the record is a living document. Read it through, check the temperatures still hold, write the date on it.
How does DwellFlow set the review date? From what the building is: a mains-fed flat with no stored water is reviewed far less often than a house with a loft tank and a vented cylinder. The date is between six months and five years out, printed in the assessment, and you are reminded when it falls due.