Legionella Risk Assessments: A Landlord's Guide to Compliance

Understanding your legal duty to assess Legionella risk in rental properties — what's required, how often, and practical steps to reduce risk.

<h2Legionella Risk Assessments: What Landlords Need to Know</h2 <pLegionella bacteria can cause <strongLegionnaires' disease</strong, a potentially fatal form of pneumonia. As a landlord, you have a legal duty under the <strongHealth and Safety at Work etc. Act 1974</strong and the <strongControl of Substances Hazardous to Health Regulations 2002 (COSHH)</strong to assess and manage the risk of Legionella in your rental properties.</p

<h3What Is Legionella?</h3 <pLegionella is a type of bacteria found naturally in water sources such as rivers and lakes. It becomes a health risk when it multiplies in artificial water systems — particularly when water is stored or distributed at temperatures between <strong20°C and 45°C</strong. The bacteria can be inhaled through water droplets (aerosols), such as from showers, taps, and spa baths.</p

<h3Your Legal Duty</h3 <pThe <strongHealth and Safety Executive (HSE)</strong states that landlords must:</p <ol <li<strongAssess the risk</strong of Legionella in their properties</li <li<strongImplement measures</strong to control any identified risks</li <li<strongKeep records</strong of assessments and any actions taken</li </ol <pThere is no legal requirement for a specific qualification to carry out a basic Legionella risk assessment in a simple domestic property. However, for more complex systems (such as those in HMOs with large water storage), a specialist assessment may be appropriate.</p

<h3How Often Should You Assess?</h3 <pThe HSE does not specify a mandatory frequency for Legionella risk assessments. However, the general guidance recommends:</p <ul <li<strongEvery 2 years</strong as standard practice</li <li<strongAfter any significant changes</strong to the water system (e.g., new boiler, plumbing alterations, long void periods)</li <li<strongWhen a new tenancy begins</strong, review the assessment to ensure it is still valid</li </ul

<h3What Does a Risk Assessment Cover?</h3 <pA basic Legionella risk assessment for a domestic rental property typically considers:</p <ul <li<strongWater temperature</strong: Hot water should be <strongstored at 60°C</strong and <strongdistributed at a minimum of 50°C</strong. Cold water should be below <strong20°C</strong.</li <li<strongWater storage</strong: Check for storage tanks, header tanks, or cylinders. Ensure they have fitted, close-fitting lids and are insulated.</li <li<strongDead legs</strong: Identify and remove any unused pipework where water can stagnate.</li <li<strongShowerheads and taps</strong: These create aerosols and should be regularly cleaned and descaled.</li <li<strongInfrequently used outlets</strong: Any taps, showers, or toilets that are not used regularly (e.g., during void periods) should be flushed weekly.</li <li<strongSystem condition</strong: Check for corrosion, scale, biofilm, and debris in the system.</li </ul

<h3Practical Steps to Reduce Risk</h3 <pMost standard domestic properties are considered <stronglow risk</strong if the following measures are in place:</p <ul <li<strongSet the hot water cylinder thermostat to at least 60°C</strong</li <liEnsure water is delivered at taps at <strong50°C or above within one minute</strong of running</li <liKeep cold water pipes insulated and away from heat sources</li <li<strongFlush through the system</strong if the property has been empty for more than a week</li <li<strongClean and descale showerheads</strong at least quarterly</li <li<strongRemove or regularly flush dead legs</strong in the plumbing</li <liEnsure water storage tanks have close-fitting lids and are free from debris</li </ul

<h3HMOs and Higher-Risk Properties</h3 <pProperties with larger or more complex water systems — such as HMOs with multiple bathrooms, communal facilities, or large storage tanks — are considered higher risk. In these cases:</p <ul <liA <strongprofessional Legionella risk assessment</strong is recommended</li <liMore detailed monitoring and record-keeping may be required</li <liConsider appointing a competent person to manage water hygiene</li </ul

<h3Penalties</h3 <pWhile there is no specific fine amount for failing to carry out a Legionella risk assessment, landlords who fail to manage Legionella risk could face:</p <ul <li<strongProsecution under the Health and Safety at Work Act</strong, with unlimited fines</li <li<strongCivil claims</strong if a tenant contracts Legionnaires' disease due to landlord negligence</li <li<strongInsurance implications</strong — many landlord insurance policies require evidence of risk management</li </ul

<h3Record Keeping</h3 <pKeep records of:</p <ul <liThe risk assessment itself (date, findings, assessor)</li <liAny remedial actions taken</li <liWater temperature checks (if you carry them out)</li <liShowerhead cleaning and system flushing during void periods</li </ul

<h3How LetSentry Helps</h3 <pTrack your Legionella risk assessment alongside other compliance checks in LetSentry. Set custom reminders so you never miss a reassessment, and store your assessment documents securely.</p

<p<emThis guide is for general information only. Refer to the <a href="https://www.hse.gov.uk/pubns/priced/l8.pdf" target="blank" rel="noopener noreferrer"HSE Approved Code of Practice L8</a and <a href="https://www.hse.gov.uk/pubns/books/hsg274.htm" target="blank" rel="noopener noreferrer"HSG274 Part 2</a for detailed guidance.</em</p

Sources: - https://www.hse.gov.uk/legionnaires/legionella-landlords-responsibilities.htm - https://www.hse.gov.uk/legionnaires/ - https://www.legislation.gov.uk/ukpga/1974/37/contents - https://www.legislation.gov.uk/uksi/2002/2677/contents/made

Published: 2026-03-06.

Last reviewed: 2026-08-30.

General summary; not legal advice.