Do Landlords Need a Legionella Risk Assessment?
Yes. Every landlord has a legal duty to assess the risk of legionella in a let property, but for a normal domestic tenancy that assessment is a short check you can carry out yourself, and there is no legally recognised legionella certificate.
The duty is real and most of the paperwork sold around it is invented. Knowing which is which saves a few hundred pounds a year across a portfolio.
The duty is to assess the risk and keep it under review, not to buy a certificate, and for an ordinary domestic let that assessment is a short check you can do yourself. Write down what you found, the control measures you put in place and the date, then revisit it when the property or its plumbing changes. Empty periods are the real risk, because water sitting still in a system is where legionella grows, so flush the outlets before a new tenant moves in. Using an agent does not move the duty off you.
Compare landlord insurance quotes alongside your safety paperwork.
- What does the law require you to do?
- Can you carry out the assessment yourself?
- Do you need a legionella certificate?
- Who is responsible if an agent manages the property?
- How much should a professional assessment cost?
- How often should you review the assessment?
- What control measures should you put in place?
- What happens to the risk when a property stands empty?
- What are the consequences of getting it wrong?
- Frequently asked questions (FAQs)
What does the law require you to do?
You have to assess the risk of your tenants being exposed to legionella and put proportionate controls in place. You do not have to sample the water, buy a certificate or hire a consultant.
Where the duty comes from
Section 3(2) of the Health and Safety at Work etc. Act 1974 extends health and safety duties to landlords in respect of the people living in their properties. The Control of Substances Hazardous to Health Regulations 2002 then treat legionella as a biological agent you have to assess and control.
There is no Control of Legionella Regulations 2010, despite the number of assessment firms that cite it. Treat any quote naming regulations you cannot find on legislation.gov.uk as a warning sign.
What HSE expects from a domestic let
The HSE guidance on landlords’ legionella responsibilities says the assessment does not require an in-depth, detailed exercise for a typical rented home. It also puts the risk in most residential water systems at low, because water gets used and turned over daily.
The technical standard behind the duty is the approved code of practice ACOP L8, supported by the HSG274 technical guidance. Both are written for cooling towers and complex buildings, not for a two-bed flat with a combi boiler.
Can you carry out the assessment yourself?
Yes, for a standard domestic let. HSE states that most landlords can assess the risk themselves and do not need to be professionally trained or accredited.
What a simple domestic assessment involves
- Sketch the system: incoming main, boiler or cylinder, any tank, every outlet.
- Check stored hot water holds 60°C and reaches the tap at 50°C within a minute.
- Check cold water runs below 20°C within two minutes at the kitchen tap.
- Note dead legs, unused outlets, header tanks and anything creating a spray.
- Write down the controls, the readings and the date you took them.
Half an hour with a digital thermometer covers most flats. File the sheet with your gas and electrical certificates.
When to Bring in a Specialist
Large or ageing storage tanks, communal risers in a block of flats, shared systems in an HMO and anything with a spa pool take you outside the simple case.
A water hygiene contractor is the right call there. Ask which standard they work to before you agree a price.
Do you need a legionella certificate?
No. HSE states plainly that health and safety law does not require landlords to obtain or produce a legionella test certificate.
Why the certificate gets sold anyway
A certificate looks like a gas safety record, so it sells well to landlords used to annual compliance documents. There is no statutory template behind it, no expiry date in law and no register that holds it.
HSE also says sampling is not usually needed for domestic hot and cold water systems. It is a tool for complex or high risk systems, not a routine landlord expense.
How to answer an agent who insists
If an agent or a contractor tells you an annual certificate is a legal requirement, ask them to name the regulation. They cannot, because none exists.
Offer your written assessment and temperature records instead. That is what an environmental health officer or a claims handler would ask to see.
Who is responsible if an agent manages the property?
You are, unless your management agreement transfers the task in writing. Handing over the keys does not hand over the legal duty.
What your management agreement should say
Read the schedule of services and find who carries out and reviews the water risk assessment. Full management contracts often include it, and let-only contracts almost never do.
Get the answer in writing before the tenancy starts. A verbal assurance is worth nothing if a council officer asks who assessed the property.
What to ask your agent to evidence
- A copy of the assessment, with the name of whoever carried it out.
- Dated temperature readings rather than a tick in a box.
- The flushing regime used between tenancies and during voids.
- What the tenant was told at check-in about showerheads and unused taps.
If several tenancies run through the same agent, ask for one schedule covering all of them. Portfolio landlords usually find a grouped visit works the same way a multi-property policy does, with one date and one price per property.
How much should a professional assessment cost?
Budget £70 to £200 plus VAT for a standard domestic let in 2026, and £250 to £450 for an HMO or a property with stored hot water and several bathrooms.
What the market charges in 2026
| Property type | Typical 2026 fee | What the fee should include |
| One or two bed flat, combi boiler | £70 to £120 plus VAT | Schematic, temperature readings, written report |
| Three or four bed house with cylinder | £90 to £200 plus VAT | As above plus cylinder and tank inspection |
| HMO or shared house | £250 to £450 plus VAT | Every outlet, communal areas, tenant guidance |
| Block with a communal tank | £300 to £700 plus VAT | Risers, tanks, plant room, remedial schedule |
| Property with a spa pool or hot tub | £350 to £800 plus VAT | Separate spa regime and a sampling plan |
| Bulk booking through an agent | £50 to £100 per property | Same scope, priced per visit rather than per job |
According to Checkatrade’s 2026 cost guide, a single domestic assessment runs at £90 to £200, falling to £50 to £100 per property on a bulk agent booking. The water treatment firm uRisk, pricing reviewed in June 2026, quotes £250 to £450 per property for residential work.
Where landlords overpay
Paying for water sampling on a combi boiler flat is the most common waste. Repeating a full assessment every twelve months on an unchanged property is the second.
On a single flat the fee should sit below what you pay for a gas safety check. Price it against your compliance budget rather than against the fear of a fine.
How often should you review the assessment?
There is no legal review interval. HSE says the law does not prescribe that the assessment be reviewed annually or every two years, so you review it when something changes.
The two year interval that is not a rule
Plenty of assessment firms describe a two year cycle as an HSE recommendation. HSE’s own landlord guidance says the opposite and points to reviewing periodically in case anything changes.
A two year diary reminder is sensible housekeeping. Presenting it as a legal deadline is where the upselling starts.
The triggers that should force a review
| Trigger | Why it matters | What to do |
| Property empty for over a month | Water sits still in pipework and cylinder | Flush every outlet, heat the cylinder, re-check |
| New boiler, cylinder or bathroom | System layout and dead legs change | Update the schematic and retake temperatures |
| Shower or tap taken out of use | A capped dead leg is left behind | Cut the redundant pipe back or flush weekly |
| Change of tenant | Occupancy pattern and habits change | Reissue the tenant guidance and flush before check-in |
| Readings off target | A control measure has failed | Fix the thermostat or blending valve, then re-read |
| Tenant reports illness | Possible exposure at the property | Investigate at once and record what you found |
Log the date and the reason every time you review. Two lines in a maintenance record shows a pattern of care.
What control measures should you put in place?
Keep the hot water hot, the cold water cold and the water moving. HSE’s summary is that short because in a domestic system those three things do almost all of the work.
Temperature control
| Control | Target | How often to check |
| Stored hot water in the cylinder | 60°C | At each review and after boiler work |
| Hot water at the tap | 50°C within one minute | At each review |
| Cold water at the tap | Below 20°C within two minutes | At each review |
| Cold water storage tank | Below 20°C, lid fitted and screened | Annually where a tank exists |
| Showerheads and hoses | Descaled and disinfected | Quarterly or at change of tenancy |
| Outlets not in regular use | Run for at least two minutes | Weekly while idle |
If the cylinder will not hold 60°C, that is a heating fault before it is a legionella problem. Get a gas engineer to check the thermostat rather than paying for a water hygiene visit you may not need.
A cold cylinder over a bank holiday is both a tenant complaint and a failed control measure, which is why landlord home emergency cover earns its place on a policy.
Stagnation and flushing
Dead legs are the classic domestic risk: a capped pipe left behind when an outside tap or an old shower came out. Cut them back rather than living with them.
Guest bathrooms and utility sinks are the other one. Anything not used weekly needs two minutes at both temperatures.
What to ask the tenant to do
Put the flushing and showerhead cleaning steps in the tenancy pack, alongside the gov.uk guidance on landlord responsibilities. Tenants are far more likely to follow one paragraph than a leaflet.
You cannot delegate the duty to a tenant, but you can show you gave clear instructions. That record is what protects you later.
What happens to the risk when a property stands empty?
Void periods are where domestic legionella risk genuinely rises, because warm water sits still in the pipework. A few weeks empty is enough to justify a full flush before the next tenant moves in.
Re-letting after a void
- Run every outlet for at least two minutes, starting furthest from the main.
- Bring the cylinder to 60°C and hold it there before check-in.
- Remove, descale and disinfect showerheads and flexible hoses.
- Check the cold water tank lid and screen if the property has one.
- Record the date, the readings and who did the work.
A long void changes your insurance position too, because most landlord policies restrict cover after 30 to 45 days empty. Unoccupied property cover fills that gap while you are between tenancies.
Hot tubs, holiday lets and short stays
A spa pool is the highest risk item you can put in a let property, because it holds warm water and turns it into aerosol. Short-let and holiday let properties with hot tubs need a written operating regime rather than a domestic checklist.
That means daily chemical checks, filter cleaning and a documented drain-down schedule. It is the one domestic case where a specialist is clearly worth the fee.
What are the consequences of getting it wrong?
Enforcement runs through health and safety law, so penalties are open ended rather than a fixed fine. In practice the realistic risks are a council notice, a civil claim and an insurance claim that gets picked apart.
Enforcement and council action
Prosecution under health and safety law carries unlimited fines and, in the worst cases, a custodial sentence. Councils can also act under the Housing Health and Safety Rating System, whose landlord guidance was reissued in June 2026.
Prosecutions of private landlords over legionella are rare. An improvement notice after a tenant complaint is far more likely, and it still costs you the works.
Where your insurance sits
Property owners‘ liability is the section that would answer a tenant illness claim, and it works much like the personal liability cover on a household policy. Most landlord insurance policies carry £2m to £5m of it as standard.
Defence and dispute costs sit under legal expenses cover, which is usually an optional section. Neither part helps much if you ignored a hazard you knew about, so the assessment paperwork is what keeps a claim alive.
The rest of the policy is buildings cover plus loss of rent if an insured event makes the property unfit to live in. Legionella remediation itself is a maintenance cost, not an insured peril.
Frequently Asked Questions (FAQs)
Yes, if they understand the system and the control measures. The law asks for competence rather than a specific accreditation, so ask what training they have had.
Twenty to forty-five minutes for a flat or small house. An HMO with several bathrooms and a stored system takes closer to two hours.
HSE says landlords are not necessarily required to record the findings. Keeping a record is still the only practical way to prove you did it.
No. An assessment asks whether conditions could let the bacteria grow, while testing samples the water to see whether it is already there.
No. Nothing in law gives one an expiry date, so a firm selling an annual renewal is selling a service rather than meeting a deadline.
Yes. HSE applies the same duty to letting a room in your own home, although the risk in an occupied house is low.
The landlord. Compliance costs are not something you can pass to a tenant as a fee under the Tenant Fees Act 2019.
The bacteria are dormant below 20°C and multiply between 20°C and 45°C. Stored hot water at 60°C kills them, which is why the cylinder setting matters.
Yes, the duty applies to every let property. The assessment is short because no stored water removes the biggest single risk factor.
Property owners’ liability may respond to a tenant illness claim, subject to the wording. An insurer will ask what you assessed and when, so keep the records.
Cooperate with the council and the health protection team, and hand over your records. Tell your insurer the same day rather than waiting for a letter.
Yes, and the commissioning flush matters more than the age of the pipework. New systems often sit full of static water for weeks before anyone moves in.