Safety

Legionella and Landlords: What You Actually Need to Do (and What You Don't)

Health & safety · 5 min read

Legionella is one of the most misunderstood duties a landlord has. At one extreme, some landlords are sold an expensive annual "legionella certificate" they were never legally required to buy; at the other, some ignore the risk entirely because it sounds technical. The honest position sits between the two — there is a real duty, but for a typical rented home it's a proportionate, low-cost one. Here's what you actually need to do, what you don't, and when to bring in a professional. This is general guidance, not legal or health-and-safety advice — check the current position with the Health and Safety Executive and on GOV.UK.

What the duty actually is

Legionella bacteria can grow in water systems and, if breathed in as a fine spray (from a shower, say), can cause Legionnaires' disease. Under general health-and-safety law, a landlord has a duty to assess and control the risk of legionella exposure to tenants. That's the whole of it: assess the risk, take sensible steps to control it, and keep it under review. It's a duty about managing a risk — not about holding a particular piece of paper.

The myth: the "legionella certificate"

Here's the part that saves most landlords money and worry: for a typical, simple domestic rental, there is no legal requirement to have a "legionella certificate," and no requirement for routine water testing or sampling. Those are things being sold, not things the law demands for ordinary homes. What the law expects is a legionella risk assessment — and for a straightforward property with a normal domestic water system, a competent landlord can often carry that out themselves, following the Health and Safety Executive's guidance. If a contractor tells you that you "must" pay for an annual certificate for a standard flat or house, treat that with healthy scepticism and check HSE guidance first.

The balance to strike: don't get mis-sold, but don't ignore it either. You almost certainly don't need a pricey certificate or annual sampling for a normal domestic let — but you do need to have carried out a proportionate risk assessment, put sensible controls in place, and be able to show you did. Confirm what's appropriate for your property with the HSE and on GOV.UK rather than relying on a sales pitch.

What a risk assessment covers

A legionella risk assessment is mostly common sense: look for the conditions bacteria like, and remove them. The things that raise risk are:

Stored or stagnant water — water tanks, or outlets that sit unused (a spare bathroom, a property between tenancies).
Lukewarm water — systems sitting in the rough temperature range (broadly 20–45°C) where legionella multiplies.
Spray-producing outlets — showers in particular, where water is breathed in as a fine mist.
Debris or scale — showerheads and taps that harbour build-up.

The controls are just as practical: keep hot water hot and cold water cold; flush through any outlets that haven't been used (especially before a new tenant moves in); clean and descale showerheads; keep tanks covered and in good order; and remove any redundant pipework where you can. Tell tenants the simple things they can do too — like flushing showers after a holiday.

When to bring in a professional

The proportionate approach flips for more complex or higher-risk situations, where a specialist assessment (and sometimes ongoing monitoring) genuinely is sensible:

Larger or complex water systems — big properties, stored-water systems, or communal tanks.
HMOs and blocks with shared supplies serving several households.
Vulnerable occupants who may be more susceptible.
Anything you're not confident assessing yourself — competence is the test, so if in doubt, get help.

What landlords should do now

Carry out a proportionate risk assessment for each property — yourself for a simple let, or via a professional for a complex or higher-risk one.
Put the simple controls in place — temperatures, flushing, clean showerheads, no stagnation.
Flush the system between tenancies and before anyone moves in.
Keep a dated record of the assessment and the controls, and review it periodically or when the property or system changes.
Check HSE and GOV.UK for what's appropriate — and don't pay for a certificate a standard domestic let doesn't need.

Legionella belongs with your other safety records — the gas certificate, the EICR and your alarms — as part of the paper trail a council relies on when it asks for your compliance records. The difference is that this one is often cheaper and simpler than landlords fear: assess it sensibly, control it, write it down, and you've met the duty without being sold something you didn't need.

Keep your legionella assessment with the rest of your records

LandlordProof stores each property's safety records and review dates in one place — so your legionella risk assessment sits alongside the gas, electrical and alarm records, dated and ready if a council or a tenant ever asks. Free for your first property.

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General guidance for UK landlords, not legal or health-and-safety advice. Legionella duties sit under general health-and-safety law and HSE guidance; what's appropriate depends on the property and its water system, and the rules can change — always check the current guidance with the Health and Safety Executive and at GOV.UK, and use a competent professional for complex or higher-risk systems.