Property Management and Legionnaire’s disease

Lorraine DindiLorraine Dindi
Last updated on:
February 3, 2022
Published on:
November 9, 2021

Read the assured shorthold tenancy agreement guide now

Read the Guide

Everything to know about controlling Legionella risk in a rental property.

Landlords and full-management letting agents throughout the UK owe their tenants a duty of care in respect of health and safety. One key element of this duty is to control the risk from hazardous biological agents such as Legionella. This article explains this duty and how a property manager can remain compliant with the relevant laws.

Legislate is a contracting platform where landlords and letting agencies can create legally valid agreements. Our tenancy agreements take Legionella risks and HSE regulations into account. View our tutorials  or sign up today!

What is Legionella?

Legionella is a bacteria that is found in man-made water systems. When inhaled, it can cause a potentially fatal pneumonia like illness known as Legionnaires' disease. Some hundreds of people are diagnosed with legionellosis in the UK every year.

What properties are at risk of Legionella?

All man-made hot and cold water systems are environments where Legionella can grow, but certain features make a particular property especially susceptible to the bacteria. These features are:  

  1. Cold water storage and older water systems, where water is stored and recirculated through the system before it is used.
  2. Communal water systems which serve multiple properties e.g. a shared fountain.
  3. Open water tanks, which are common in older buildings, since water is likely to be left to stagnant.
  4. Properties that are left vacant for significant periods of time. This is concerning given the properties that have been empty for a long time during the COVID-19 pandemic.
  5. Water droplets, spray or mist which is dispersed into the air through showers, hot tubs, hose sprinklers, dishwashers, washing machines, whirlpool baths etc.
  6. Water temperatures between 20°C and 45°C, which is the range where the bacteria thrives.
  7. Water that contains (or is in contact with) deposits such as rust, scale, sludge, slime and biofilm. These deposits provide nutrients for the Legionella bacteria to feed on.

It should be noted that properties with small water systems where daily water usage is enough to turn over the entire system are generally considered low risk. The same is true for properties where cold water comes directly from the mains water supply rather than a water tank, properties where toilets and sinks are the only outlets, and where hot water comes from instantaneous water heaters such as combination boilers or electric showers.

What are a letting agent or landlord's responsibilities?

The Control of Substances Hazardous to Health Regulations 2002 and the L8 Approved Code of Practise: Legionnaires’ Disease set down the legal responsibilities of people who control residential properties in respect of Legionella. Below is an overview of the legal framework which must be followed in order to control the risk of Legionella in water systems and water storage tanks.


This is a simple assessment of the potential risk from exposure to Legionella in domestic properties which can be carried out by any competent person such as the landlord themselves. The assessor needs to inspect all man-made water systems and equipment in a property for potential hazards, in order to determine whether or not the system is likely to create a risk from Legionella exposure. The assessor should identify which tenants are at risk, and depending on factors such as age and lifestyle, identify how they are at risk. For example, smokers or people with respiratory problems will be considered higher risk. Taking this into account, the assessor should then evaluate the level of risk associated with each identified hazard.


While it’s not a legal requirement to keep written records of the findings of the Legionella risk assessment, it is a sensible thing for a landlord to do. The record must include the details (name and position) of the assessor and any significant findings of the assessment. The state and condition of the water systems should be noted down, along with the frequency with which they are used. If any Legionella risks have been discovered, information should be included on what the adequate control measures are and when they shall be implemented. Moreover, if there have been previous inspections of the water systems, then the date they were carried out should be recorded, as well as any controls which were implemented as a result of that inspection.


The landlord must remove the sources of potential risk or implement appropriate control measures to reduce the risk level. If the risk level was found to be low, then simple measures will ensure that  it stays low. Control measures must be proportionate and adequate, and may include the following:

  1. Avoid debris getting into the water system by fitting water tanks with tight seals and keeping boilers in good working order.
  2. Clean, descale and disinfect shower heads at least every 6 months.
  3. Flush out the system before letting the property.
  4. Keep hot water in the system hot and cold water in the system cold.
  5. Keep taps clear of limescale and mould, which can feed the bacteria.
  6. Remove any faulty or redundant pipework.
  7. Run showers and taps which are not used regularly for at least 2 minutes every week, while staying out of the way during this time.
  8. Set the hot water cylinder (calorifier) to 60°C where the Legionella bacteria is killed.
  9. When a property has been or will be empty for a while, to prevent outbreaks:
  • run outlets at least once a week in order to flush the system so water does not stagnate;
  • drain the property’s plumbing system.


It is important for a landlord to keep on controlling the risks because if a tenant were to contract Legionnaires’ disease from the water system, the landlord would be liable to prosecution under the Health and Safety at Work Act 1974 and a fine of up to £20,000. The landlord would need to go to court and attempt to prove that they did indeed satisfy their legal duty to assess and control the risk of Legionella in that rental property.


It is recommended that Legionella risk assessments are conducted every 2 years or at the start of a new tenancy. During a tenancy, it is important to periodically review the assessment especially when there are significant changes to the property's water system. Checks can be made when the landlord/agent is visiting the property for routine maintenance or gas safety checks.

Curious about automated data extraction from documents?

Do tenants have any Legionella responsibilities?

Since tenants are the ones who interact daily with a property’s water system, they have their part to play in mitigating the risk of Legionella exposure. The following is a list of measures that tenants should be advised to take during the course of their tenancy:

  1. Clean and disinfect shower heads regularly.
  2. Descale taps and shower-heads regularly if the property is in a hard water area.
  3. Flush through any water systems if the property is left unoccupied for a while.
  4. Not interrupt any control measures that have been put in place.
  5. Not tamper with controlled temperature settings e.g. that of the calorifier.
  6. Tell the landlord if the hot water is not being heated properly.
  7. Tell the landlord of any problems with the water system e.g. leaks, pipeline corrosion.
  8. Tell the landlord if the tenant will be leaving the property empty for a while.

How to create a tenancy agreement which clearly states the property's legionella testing requirements

Legislate is a contracting platform where landlords and letting agencies can create legally valid agreements. Its tenancy agreements take Legionella risks and regulations into account. Book a demo of Legislate, sign up or receive an invite from an existing member.

For reminders on what you need to be checking in your rental properties, you can sign up for updates by joining our newsletter.

‍The opinions on this page are for general information purposes only and do not constitute legal advice on which you should rely.

Create your assured shorthold tenancy agreement now

Get Started

Keep Reading

Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.