Legionella Prevention for Landlords and Commercial Properties

Legionella Prevention for Landlords and Commercial Properties

Managing a property involves more than maintaining walls, roofs, heating and electrical systems. The water system also requires appropriate attention, particularly where landlords, businesses and commercial property managers are responsible for premises used by other people.

Legionnaires' disease is a potentially fatal form of pneumonia associated with inhaling tiny airborne droplets containing viable Legionella bacteria. Legionella is commonly found in water, but poorly managed hot and cold water systems can create conditions that allow the bacteria to multiply.

For landlords and businesses, the objective should be straightforward: understand the water system, identify foreseeable risks and put appropriate control measures in place.

1. Landlords should understand their water system

A common mistake is assuming that a property is too small to require proper consideration.

The size of a building alone does not determine whether water hygiene requires attention. Different types of systems can present different risks, and the way a property is occupied can also influence how water behaves within the system.

A landlord should know:

How hot water is stored and distributed
Whether the property has a cold water storage tank
Whether there are hot water cylinders or calorifiers
Which outlets are regularly used
Which outlets may remain unused
Whether there are TMVs
Whether plumbing has been altered
When tanks and associated equipment were last inspected
Whether previous water hygiene checks have identified issues

Understanding the system is the starting point for sensible Legionella control.

2. Rental properties can experience periods of stagnation

One of the practical challenges for landlords is changing occupancy.

A property can remain empty between tenants, during refurbishment or while awaiting a sale. During this period, water may remain stagnant in sections of the system.

The same issue can occur in commercial properties where offices, meeting rooms, staff facilities or other areas are rarely used.

Stagnant water can favour Legionella growth, which is why HSE guidance recommends regular flushing of infrequently used outlets as part of appropriate control measures.

Landlords and property managers should establish a clear procedure for managing unused outlets rather than relying on occupants to remember to run them.

3. Temperature control is a key part of prevention

Hot and cold water temperatures should be managed carefully.

Where temperature is being used as the primary control strategy, HSE guidance states that hot water should be stored at least at 60°C and distributed so that it reaches at least 50°C within one minute at outlets. Cold water should be maintained, where possible, below 20°C.

Regular monitoring can help identify whether a system is operating as intended.

For more complex properties, checks may include the hot water storage temperature, flow and return temperatures and temperatures at selected sentinel outlets. HSE guidance recommends monthly temperature checks at relevant sentinel points for hot water systems.

Temperature records are particularly useful because they create evidence of ongoing monitoring rather than relying on assumptions about how a system is performing.

4. Commercial properties need a structured approach

Businesses often have more complicated water systems than a typical residential property.

An office, restaurant, gym, hotel, retail premises, warehouse or mixed-use building may contain multiple bathrooms, showers, kitchens, storage tanks, hot water cylinders or longer pipe runs.

The larger or more complex the system, the more important it becomes to understand its layout and operating conditions.

A suitable water hygiene programme may involve:

A Legionella risk assessment
A schematic of the water system
Temperature monitoring
Tank inspections
Cleaning and disinfection
Showerhead maintenance
Outlet flushing
Water sampling where appropriate
Records of completed checks and remedial actions

The precise measures should be based on the risk assessment and characteristics of the system.

5. Do not ignore dirty or poorly maintained tanks

A storage tank that has not been inspected for years should not simply be assumed to be in good condition.

Sediment, scale and debris can accumulate within tanks and contribute to conditions that support bacterial growth.

HSE guidance recommends maintaining cold water storage tanks in a clean condition and checking them at least annually, with remedial work undertaken where necessary.

The same principle applies to hot water storage equipment. Inspection can help identify scale, sludge and other conditions that may affect water quality and system performance.

Where cleaning is necessary, it should be carried out as part of a properly considered water hygiene procedure.

6. Showerheads and hoses need regular attention

Showers deserve particular consideration because their operation can produce airborne droplets.

Scale and deposits can build up on showerheads and hoses, creating an environment that requires routine maintenance.

HSE guidance recommends cleaning and descaling showerheads and associated hoses quarterly, or at a frequency determined by the risk assessment.

For landlords, this should form part of property maintenance rather than being treated as an optional cosmetic task.

For businesses with multiple showers, a documented maintenance schedule makes it easier to demonstrate that the equipment is being managed consistently.

7. Keep records and act on problems

Good Legionella control is not simply about carrying out checks. Problems identified during those checks need to be addressed.

If a temperature reading is outside the expected range, for example, the appropriate response may involve investigating the cause rather than simply recording the number and moving on.

Possible causes could include:

Faulty heating equipment
Poor circulation
Incorrect thermostat settings
Scale or sludge
Changes to pipework
Low system usage
Inadequate insulation
Faulty TMVs or other components

Records should show what was checked, what was found, what action was recommended and whether that action was completed.

This creates a much stronger management process than a collection of disconnected maintenance invoices.

8. Refurbishment can create new risks

Landlords and businesses should consider Legionella control whenever plumbing systems are altered.

A refurbishment may introduce new outlets, pipework branches or areas that receive little use.

Before a modified system is returned to normal operation, appropriate cleaning, flushing, disinfection or testing may need to be considered.

Planning this work in advance can also prevent delays when a property is approaching handover or reoccupation.

What should landlords and businesses do next?

Begin with a review of the property.

Identify the type of water system, storage arrangements, hot water equipment and outlets. Establish whether the property has areas of low use or periods when it remains empty.

Review existing maintenance records and determine when tanks, showerheads, TMVs and other relevant equipment were last inspected or serviced.

If there is no clear record of the system's condition, a professional Legionella risk assessment can provide a structured starting point.

Depending on the findings, further work could include water testing and sampling, tank cleaning, chlorination, pipework disinfection, temperature monitoring or remedial plumbing work.

Professional water hygiene support for landlords and businesses

London Chlorination and Water Treatment supports landlords, commercial property owners, businesses, property managers and homeowners with practical water treatment and Legionella control services.

From tank cleaning and water testing to chlorination, pipework disinfection and Legionella risk assessments, the right service can be selected according to the condition and requirements of the property.

If you manage a rental property, commercial premises or business building and want greater confidence in the condition of your hot and cold water system, contact London Chlorination and Water Treatment to discuss the property and request a quotation.