Legionella is one of those words that can make a straightforward landlord task sound like a major engineering project. The reality is usually much more manageable.
For most standard rental homes, a legionella risk assessment for landlords is a practical review of the hot and cold-water system. You identify where water could stagnate, check that temperatures are properly controlled, and put sensible measures in place to reduce risk.
That said, “manageable” does not mean “ignore it”. Landlords, property managers and letting agents have clear responsibilities for protecting tenants from health hazards, including risks associated with water systems.
This guide explains what you need to know in 2026, including the difference between an assessment and testing, when professional support is sensible, and how to keep your documentation in order.
What are a landlord’s Legionella responsibilities?
If you rent out a property, you have a legal duty to protect your tenants from health and safety risks. This applies whether you own:
- A single buy-to-let flat
- A family house
- An HMO
- A property with stored hot or cold water
- A room within your own home
- A portfolio managed by an agent
These landlord legionella responsibilities generally involve identifying the risks, putting suitable control measures in place, maintaining those controls and reviewing them when circumstances change.
The Health and Safety at Work etc. Act, COSHH and the principles set out in the HSE’s Approved Code of Practice L8 all inform how landlords should manage the risk.
For a typical domestic property, the approach should be proportionate. You do not usually need a complicated technical report simply because the property has a bathroom and a boiler. However, you do need to understand how the system works and whether any features create additional risk.
That distinction is important. Compliance should be practical, but it should never be treated as a box-ticking exercise.
What does a Legionella risk assessment cover?
A suitable assessment considers the property’s actual water system, not just its address and number of bedrooms.
You should identify:
- Whether the property has a combi boiler or stored hot-water cylinder
- Whether cold water is supplied directly from the mains
- Whether a cold-water storage tank is present
- The location of tanks, cylinders, boilers and pipework
- Showers and other outlets that can create water droplets
- Little-used taps, showers or toilets
- Redundant pipework and potential dead legs
- Long periods of vacancy
- Any vulnerable occupants who may face greater health risks
A small flat with a mains-fed cold-water supply and regularly used combi boiler may present a relatively low risk. An HMO with multiple bathrooms, a hot-water cylinder, long pipe runs and irregular occupancy requires closer attention.
Do not assume that every property in your portfolio has the same risk profile. A standardised document may be convenient, but your assessment should reflect the system and usage pattern in each home.
Temperature, movement and maintenance are your first controls
For most domestic properties, the basic principles are refreshingly straightforward:
- Keep hot water hot
- Keep cold water cold
- Keep water moving
- Maintain the system properly
Stored hot water is generally controlled at around 60°C, while outlets should reach a suitable temperature in line with the system design and relevant guidance. Cold water should remain suitably cool, commonly below 20°C.
These figures should not encourage you to turn the boiler up without considering scalding risk. Hot water controls must protect tenants from both bacterial growth and burns. This is particularly important in HMOs, family homes and properties occupied by vulnerable people.
You should also reduce opportunities for stagnation. Remove redundant pipework where appropriate, ensure storage tanks are properly covered, and investigate outlets that are rarely used.
Showerheads and hoses need regular cleaning and descaling because they can collect scale, sediment and biofilm. Tenants should know how to report problems such as water that is not heating properly, unusually warm cold water or poor flow.
Simple controls work best when someone is clearly responsible for carrying them out.
Legionella testing for landlords: is it actually required?
This is where a lot of confusion enters the conversation.
Legionella testing for landlords is not normally the same thing as carrying out a risk assessment. Routine microbiological sampling is not usually required for standard domestic hot and cold-water systems, and landlords are not generally required to obtain a “Legionella certificate”.
Instead, temperature monitoring and sensible system management are usually the primary controls.
Laboratory testing may be appropriate in specific circumstances, such as:
- A complex or communal water system
- Persistent temperature-control problems
- A known or suspected case of Legionnaires’ disease
- A history of contamination
- Unusual system design or extensive stored water
- A property occupied by particularly vulnerable residents
- A risk assessment that identifies sampling as necessary
Do not pay for routine testing simply because someone tells you that every landlord must have a certificate. Ask what risk the test addresses and whether it is supported by the property’s actual system.
Equally, do not dismiss testing where the risk assessment shows that it is appropriate. Good compliance means matching the control measure to the risk.
What changes for HMOs and properties with stored water?
HMOs often require more detailed consideration because they have more outlets, more occupants and more varied usage patterns.
One tenant may use a shower every day. Another may work away during the week. A third bedroom may remain empty for several months. That creates different patterns of water use throughout the same building.
An assessment for an HMO should focus on:
- Shared bathrooms and kitchens
- Ensuite facilities
- Stored hot or cold water
- Multiple showers
- Little-used outlets
- Long or complicated pipe runs
- Responsibility for temperature checks and flushing
- How tenants receive information about maintaining controls
Properties with stored water also deserve closer attention. Tanks and cylinders can hold water for longer periods, particularly when demand is low. Check that tanks are clean, covered and properly maintained, and ensure that the control scheme explains who monitors the system.
If the water system is complex, do not guess. Obtain competent advice and ensure the recommendations are specific enough for the landlord or managing agent to follow.
Do not overlook vacant properties
Vacancy is a common source of stagnation. A property can be empty between tenancies, during refurbishment, while awaiting sale or because an HMO room is temporarily unoccupied.
Your plan should explain what happens during that period.
Depending on the property and system, this may include:
- Flushing hot and cold outlets
- Paying particular attention to little-used taps and showers
- Checking temperatures before reoccupation
- Cleaning or descaling showerheads
- Investigating unusual flow or temperature issues
- Recording who completed the checks and when
HSE guidance generally highlights the importance of maintaining water movement, with outlets used regularly where practical. However, there is no single flushing routine that suits every property.
A compact, occupied flat is not managed in the same way as a large vacant HMO with stored water. The right approach depends on the system, length of vacancy and findings of the assessment.
Before a new tenant moves in, make sure the property is not simply clean and presentable, but also properly prepared from a water-safety perspective.
Who can carry out the assessment?
For a simple domestic system, a competent landlord may be able to assess the risk themselves. HSE guidance does not automatically require every landlord to appoint an external specialist.
However, property ownership does not automatically equal competence.
You should be able to understand the water system, identify relevant hazards, implement suitable controls and recognise when specialist support is needed. If you cannot do that confidently, arrange an assessment through a competent professional.
Professional support is particularly useful where you manage:
- Multiple properties
- HMOs
- Communal or stored-water systems
- Properties with long void periods
- Homes occupied by vulnerable tenants
- Buildings with a history of plumbing alterations
- Portfolios where responsibilities are split between landlords, agents and contractors
A clear assessment should tell you what the risks are, what needs to happen next and who is responsible. A report that sits unread in a property folder has limited value, however impressive the cover page may be.
Keep practical records and review them when circumstances change
Although the law does not prescribe a fixed annual or biennial review for every domestic property, keeping clear records is sensible and helps demonstrate that you have acted responsibly.
Record:
- The date of the assessment
- The water-system design
- Identified risks
- Control measures
- Temperature checks, where applicable
- Flushing during vacancy
- Cleaning and maintenance
- Remedial actions
- Plumbing alterations
- The responsible person
- Review dates and reasons for updates
Review the assessment after a boiler, cylinder, tank or shower is replaced. Review it when pipework changes, occupancy changes significantly, or a property becomes vacant for an extended period.
The paperwork should describe the property as it exists today, not as it looked several tenancies ago.
Why choose Evestaff for Legionella Risk Assessments?
Founded in 2012, Evestaff Property Inventory Clerks has more than 12 years of experience supporting landlords, property managers and letting agencies across London and Kent.
Our highly experienced clerks use modern technology and a meticulous, precision-focused approach to create clear documentation that is easy to review and share. That matters when you are managing one property, coordinating an HMO or overseeing a larger portfolio.
Evestaff Property Inventory Clerks are accredited members of ECMK, reinforcing our commitment to professional standards and dependable reporting. Our approach reflects our brand archetype: The Perfectionist. We focus on the details because property compliance rarely falls apart in the obvious places.
If you need support with a legionella risk assessment for landlords, explore the services available through Evestaff Property Inventory Clerks.
New customers can also receive 10% off their first booking when booking directly. And if you know another landlord, agent or property professional who would value a careful, reliable service, you can use our Refer a Friend offer.
A practical Legionella checklist for landlords in 2026
Before you close the property file, ensure that you can answer “yes” to the following:
- Have you assessed the actual hot and cold-water system?
- Have you identified tanks, cylinders, showers and little-used outlets?
- Have you considered stagnation during vacancy?
- Are temperature controls appropriate for the system?
- Are showerheads and hoses included in the maintenance plan?
- Is someone clearly responsible for managing the controls?
- Does that person have the necessary knowledge and experience?
- Are significant checks and remedial actions recorded?
- Will you review the assessment after changes to the system or occupancy?
- Have you avoided paying for unnecessary routine testing or certificates?
Legionella risk management is not designed to frighten responsible landlords. It is designed to help you understand the property, control foreseeable risks and protect your tenants.
Keep the approach proportionate, keep the records clear and do not allow a quiet property or a busy portfolio to hide a water-system problem. That is how you make Legionella compliance much less scary — and considerably more useful.
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