Legionella risk assessments for landlords: what the law asks, and what it does not

A landlord must assess the risk of legionella in a rented home’s water system and keep that risk under control, but for most homes this is a short, simple job, and there is no such thing as a legionella certificate in law. That is the position of the Health and Safety Executive (HSE), whose guidance on landlords’ responsibilities is the source for everything below. Legionnaires’ disease is a potentially fatal pneumonia caught by breathing in small droplets of contaminated water, and any hot and cold water system can let the bacteria grow, so the duty is real even though meeting it is usually cheap. The duty and the HSE guidance apply in England, Wales and Scotland, and Scotland’s Repairing Standard guidance adds more for private lets. Northern Ireland has its own health and safety law and its own regulator. Both are summarised below.

Who the duty applies to

HSE treats as a landlord anyone who rents out a property they own under a lease or licence shorter than seven years, including someone letting a room in their own home. Under the Health and Safety at Work etc. Act 1974 a landlord is regarded as self employed and must run the letting so that tenants are not exposed to health and safety risks. The Control of Substances Hazardous to Health Regulations (COSHH) set out how to assess and control a biological hazard like legionella, and HSE’s Approved Code of Practice L8 explains how those rules apply to anyone in control of premises, landlords included.

What the assessment involves

HSE puts it plainly: there is a duty to assess the risk, but it does not have to be an in depth, detailed assessment. Most homes are low risk because the water is used every day. HSE’s example of a typical low risk home is one where:

• daily use turns over all the water in the system;
• cold water comes straight from the mains, with no stored water tank;
• hot water comes from an instantaneous or low volume heater supplying outlets at 50°C; and
• the only outlets are toilets and wash hand basins.

Most real homes add a shower, a bath or a stored hot water cylinder to that picture, which is why the assessment still looks at each one rather than assuming.

In practice the assessment asks a few questions about each home: is there a cold water tank, and is it covered; is there a hot water cylinder, and what temperature is it set to; is there pipework that no longer goes anywhere; are there outlets nobody uses; and will the home stand empty. A simple assessment may well show there is no real risk and nothing more to do. HSE says most landlords can carry it out themselves without training or accreditation, or can arrange for someone else to do it.

The controls that keep the risk low

HSE’s rule of thumb is to keep the hot water hot, the cold water cold, and keep it moving. The simple measures it lists are:

• flushing the system through before a new tenancy starts;
• keeping debris out, for example a tight fitting lid on any cold water tank;
• setting a hot water cylinder so water is stored at 60°C;
• removing any redundant pipework where water would sit still.

Combi boilers and electric showers lower the risk further, because they store no water.

What to tell tenants

HSE says tenants should be told about the controls and asked to keep them going, for example to:

• leave the temperature setting on the hot water cylinder alone;
• clean and disinfect showerheads regularly;
• tell the landlord or agent if the hot water is not heating properly or anything else is wrong with the system.

A short note in the move in pack covers this, and a dated copy of it shows the information was given.

Empty properties

Water standing still is where the risk rises, so empty periods need managing. HSE’s general principle is that hot and cold outlets should be used at least once a week. For a home that will be empty for a long time, such as student accommodation over the summer, it suggests a flushing regime or draining the system. For an agency, the gap between tenancies is the moment to diary a flush before the next tenant moves in.

Testing, certificates and records

• No certificate. HSE says health and safety law does not require landlords to obtain or produce a legionella test certificate.
• Testing is rarely needed. Sampling the water for legionella is not usually required in a domestic system. Checking water temperatures is a different thing, and a reliable way to confirm the system is under control.
• Writing it down. Recording the findings is a legal duty only for employers with five or more employees, but HSE says it may be wise to keep a record of what has been done for your own purposes.
• Reviewing it. The law sets no annual or two yearly review in England and Wales. HSE says to review the assessment periodically in case anything changes, and that where access is difficult, checks can be made during visits such as the annual gas safety check or routine maintenance.

HSE and councils do not proactively inspect rented homes for this or ask to see assessments. The reason to keep the record anyway is the one HSE gives: if a tenant caught Legionnaires’ disease from the water system, the landlord could be prosecuted and would have to show a court they had met their duty. A dated assessment, the controls in place and the note given to tenants are that evidence.

What to keep on file for each property

• The assessment, its date and who carried it out.
• The water system as found: tank or no tank, cylinder or combi, any redundant pipework removed.
• The controls in place, such as the cylinder temperature setting.
• The information given to tenants, and when.
• Flushes between tenancies and during empty periods, with dates.
• When the assessment was last reviewed, and what changed.

Wales, Scotland and Northern Ireland

• Wales. The same duty and the same HSE guidance apply, because the Health and Safety at Work etc. Act 1974 covers Wales. For HMOs, the Management of Houses in Multiple Occupation (Wales) Regulations 2006 add that any water storage tank must be kept clean and in working order, with a cover over it.
• Scotland. The same duty applies: the 1974 Act covers Scotland too. Scotland’s statutory Repairing Standard guidance for private landlords goes further: every water system must be assessed before the home is first let, the assessment reviewed at intervals of no more than two years, and the system flushed before letting if that has not been done in the previous two years.
• Northern Ireland. The equivalent law is the Health and Safety at Work (Northern Ireland) Order 1978 and the Control of Substances Hazardous to Health Regulations (Northern Ireland) 2003, and the regulator is the Health and Safety Executive for Northern Ireland (HSENI). Its legionella guidance says that landlords, as people in control of premises, must understand the health risks from legionella, and that every water system needs a risk assessment, though not every system needs elaborate control measures.

Where this lives in Verixad

Verixad has a Legionella document type, so each property’s assessment is filed on its record with its date, and a letting agency can set it as a document every property must hold, so a property without one shows as a gap. Because the law sets no review interval, the review date is yours to choose; a task with a due date and an owner keeps it, and the flush before each new tenancy, from being forgotten. The certificates guide puts legionella beside the certificates that do have fixed renewal dates.

General information rather than legal advice. Checked on 23 October 2026 against HSE’s guidance on legionella and landlords’ responsibilities.