Who Is Responsible for Legionella in a Rented Property?

The landlord, as duty holder, is legally responsible for assessing and controlling legionella risk in a rented property under the Health and Safety at Work etc. Act 1974 and COSHH. They must assess the risk, apply controls, keep written records and review them periodically.

That duty applies to every private let, from a single flat to a large house in multiple occupation. It does not require a laboratory test or a certificate for most homes, which is where much of the confusion, and a fair amount of mis-selling, begins.

Who is the duty holder for legionella in a rented property?

Under health and safety law the legal duty sits with the person in control of the premises. For most private lets that is the landlord, and this is the heart of any landlord legionella responsibility. If you own and let a property, you are the duty holder and that duty cannot be signed away.

Where a managing agent runs the property, responsibility for specific tasks can be shared or delegated in writing. The written agreement should state clearly who assesses the risk, who carries out flushing and temperature checks, and who keeps the records. Even with an agent in place, the landlord keeps the overarching legal duty and should confirm the work is actually being done.

In a block of flats or an HMO with shared tanks and pipework, the freeholder or their appointed agent is usually responsible for the communal water system, while the landlord of each let remains responsible for the water system inside their own property. This is what people are really asking when they search for who is responsible for legionella checks.

What is a landlord legally obligated to do?

The landlord legionella duty breaks down into four practical obligations, drawn from the Health and Safety at Work etc. Act 1974, COSHH, the Approved Code of Practice ACOP L8 and the technical guidance in HSG274:

• Assess the risk. Identify where legionella could grow and spread in the water system, such as stored water, infrequently used outlets and dead legs.
• Control the risk. Put proportionate measures in place, mainly temperature control and flushing.
• Record what you find and do. Keep a written risk assessment and a note of the checks you carry out.
• Review it. Revisit the assessment periodically, and whenever the system, the building or the occupants change.

None of this requires a consultant for a straightforward home. A landlord who understands their own system can be the competent person, and our guide to doing your own assessment explains how far that goes. The point is not to prove the property is safe, but to record that you have assessed and controlled the risk sensibly.

HSE, Legionella and landlords' responsibilities; ACOP L8 and HSG274 Part 2

The testing myth: a risk assessment is not a legionella test

This is the single most misunderstood point, and it is worth being precise. A legionella risk assessment is a proportionate review of your water system: its layout, temperatures, storage, little-used outlets and general condition. A legionella test is something different. It means taking water samples and sending them to a laboratory to count bacteria in colony-forming units per litre.

The law asks landlords for the assessment, not the test. HSE guidance is explicit that routine sampling is not required for most domestic hot and cold water systems, because well-run temperature control is a more reliable safeguard than an occasional sample. There is also no legal "legionella certificate" for landlords in England and Wales, unlike the gas safety certificate or the EICR.

This matters because some letting agents and companies sell a "legionella test certificate" as though it were a legal requirement. For a typical low-risk rental it usually is not. Sampling has its place, for example where a control scheme is not working, where there are particularly vulnerable occupants, or where the risk assessment specifically recommends it, and our page on sampling and action levels covers when the 100 and 1,000 CFU per litre thresholds come into play.

Control measures every landlord should apply

Legionella multiplies in still water between 20°C and 45°C. The practical controls all work by removing that opportunity, and each one should be recorded rather than simply assumed. Our free risk assessment template gives you a place to log every check as you make it.

• Temperature. Store hot water at 60°C so it reaches outlets at 50°C, and keep cold water below 20°C. See our temperature control guidance for the detail.
• Flush after void periods. Run all taps and showers for a few minutes before a new tenancy, and after any spell the property has stood empty, to clear stagnant water. Our flushing guide explains the method.
• Protect stored water. Make sure cold water tanks have close-fitting lids to keep out debris, insects and light.
• Keep outlets clean. Descale and disinfect showerheads and hoses, where scale and biofilm can shelter bacteria.
• Remove dead legs. Cut out redundant pipework where water sits and stagnates. Our page on dead legs shows what to look for.

When a rented property is higher risk

Not every let carries the same risk, and the assessment should be proportionate to what you actually have. A small flat fed straight from the mains, with a combi boiler and no stored water and no shower, sits at the lower end. Even then, the duty to assess and record still applies.

Risk rises where the property has any of the following: a cold water storage tank or a hot water cylinder, showers or spray taps that create fine droplets, long or complex pipe runs, or frequent void periods where water stagnates. Houses in multiple occupation and blocks with communal tanks warrant closer attention.

Tenant vulnerability also matters. People over 45, smokers, and those with weakened immune systems or chronic lung or heart conditions are more susceptible to infection, so a let occupied by higher-risk tenants deserves a more careful eye on the controls.

Scotland, tenants, and keeping the assessment current

The underlying duty is UK-wide, but the framing differs. In England and Wales it flows from the Health and Safety at Work etc. Act 1974 and COSHH. In Scotland the model private residential tenancy agreement states plainly that the landlord must take all reasonable steps to reduce the risk of legionella, so the obligation is spelled out in the tenancy itself.

Tenants have a part to play too. They should flush taps and showers if they return from a long absence, keep showerheads clean and descaled, and report discoloured water, unusual smells or temperature problems promptly. A landlord cannot control what happens day to day inside an occupied home, so clear guidance to tenants is part of managing the risk.

Finally, the assessment is not a one-off. Review it periodically, commonly every two years, and sooner if you alter the plumbing, add a shower, change the boiler or cylinder, or the property changes use. If you are still unsure whether your situation needs one at all, our page on whether you need a risk assessment works through it.