Legionella Prevention for Landlords and Commercial Properties

Managing a property means more than keeping the building in good condition. It also means understanding the systems that occupants rely on every day, including the water supply.

For landlords, property managers and commercial building operators, Legionella prevention is an important aspect of water hygiene management.

Legionella bacteria can multiply in poorly maintained water systems, particularly where water stagnates, temperatures are unsuitable or deposits accumulate.

Taking a preventative approach helps reduce potential exposure, support regulatory responsibilities and avoid unnecessary disruption.

Why Legionella Prevention Matters

Legionella bacteria can cause Legionnaires' disease when contaminated water droplets are inhaled.

Building water systems can create exposure risks through showers, taps and other equipment that produces aerosols.

Landlords and employers have relevant health and safety responsibilities, although the precise control measures needed depend on the property and the identified risks.

A suitable Legionella risk assessment is an important starting point for understanding and managing those risks.

1. Identify Who Is Responsible

In rented and commercial properties, several parties may be involved in managing water systems.

These can include landlords, managing agents, facilities managers, maintenance contractors and employers.

Responsibilities should be clearly defined so inspections, temperature monitoring, repairs and other control measures are not overlooked.

For shared or managed premises, it is particularly important to establish who controls the relevant systems and who is authorised to arrange remedial work.

2. Understand the Building's Water System

An effective prevention programme begins with understanding how water is stored, heated and distributed.

Relevant components may include:

• Cold water storage tanks

• Hot water cylinders and calorifiers

• Distribution pipework

• Showers, taps and other outlets

• Thermostatic mixing valves

• Infrequently used sections

• Secondary circulation systems

Complex buildings may benefit from schematic diagrams and accurate maintenance records.

Where existing equipment is unsuitable or repeatedly causes problems, hot and cold water system replacements may be considered following professional assessment.

3. Maintain Appropriate Water Temperatures

Temperature control is one of the primary ways to limit Legionella growth.

In conventional temperature-controlled systems, UK guidance generally recommends storing hot water at 60°C or above and distributing it so that appropriate outlet temperatures are achieved.

Cold water should generally be maintained below 20°C where possible.

The exact monitoring arrangements should reflect the building's water system and applicable risk assessment.

Temperature problems should be investigated promptly, as chemical treatment alone will not resolve an underlying heating or circulation fault.

4. Prevent Water Stagnation

Periods of low water use can increase the potential for stagnation.

This is relevant to vacant rental properties, unused office areas, seasonal accommodation and rarely used showers.

Appropriate flushing procedures can help maintain water movement, but the required frequency should be determined by the control programme.

Where redundant or problematic pipework is identified, alterations or pipework disinfection may form part of the required works.

Properties returning to use after extended closures may need additional checks before occupants return.

5. Inspect and Maintain Water Storage Tanks

Poorly maintained storage tanks can accumulate sediment, scale and other deposits.

Regular inspection helps identify issues such as damaged covers, contamination, deterioration and unsuitable water conditions.

When cleaning is necessary, hot and cold water tank cleaning can help restore appropriate hygiene conditions.

Tank cleaning should be planned according to system condition, risk assessment findings and applicable maintenance requirements.

6. Maintain Showers and Water Outlets

Showers and other aerosol-producing outlets deserve particular attention because they may create a route of exposure.

Routine maintenance may include:

• Cleaning and descaling showerheads and hoses

• Checking outlet condition

• Identifying seldom-used facilities

• Maintaining thermostatic mixing valves

• Investigating unsuitable temperatures

• Addressing leaks and damaged fittings

The frequency and scope of these activities should reflect the building's risk assessment and written control scheme, where applicable.

7. Know When Chlorination Is Appropriate

Chlorination can help manage specific contamination problems, but it is not a universal preventative treatment.

A professional assessment may recommend water system chlorination following certain alterations, contamination events or other circumstances requiring disinfection.

Where physical deposits are present, cleaning may be necessary before disinfection.

Any treatment should be supported by measures that address the underlying causes of contamination.

8. Arrange Water Testing When Indicated

Water sampling can be useful when a risk assessment, control programme or applicable guidance identifies a need for testing.

Testing may help investigate possible contamination, verify certain remedial works or assess whether controls are effective.

However, routine sampling is not automatically necessary for every property.

Our water testing and sampling services can support property owners and managers where laboratory analysis forms part of their water hygiene requirements.

9. Keep Records and Review Your Procedures

Accurate records help demonstrate how a property's water hygiene risks are being managed.

Depending on the system, records may include:

• Legionella risk assessment findings

• Temperature monitoring results

• Flushing activities

• Tank inspections and cleaning

• Maintenance and remedial work

• Sampling results, where applicable

• Assigned responsibilities

• Dates of reviews and corrective actions

Records should be kept in accordance with applicable legal duties and guidance.

Risk assessments should also be reviewed whenever circumstances change or there is reason to believe existing controls are no longer suitable.

Legionella Prevention Support Across London

London Chlorination & Water Treatments works with landlords, managing agents, commercial property operators, contractors and councils across London.

Our services include Legionnaires assessments, water tank cleaning, pipework disinfection, chlorination and water testing.

Whether you manage a single rental property or a larger commercial building, understanding the system and addressing risks early is essential to responsible water hygiene management.

Contact London Chlorination & Water Treatments to discuss your property and request a free, no-obligation quote.