Legionella checks: what are they?

As a landlord, you have an obligation to protect your tenants. And under the Homes (Fitness for Human Habitation) Act 2018 and the Control of Substances Hazardous to Health Regulations (2002), you have a specific legal responsibility to keep your rented property safe and free from health hazards.

One of the potential hazards in any property is legionella – but what exactly is it and what do you need to do minimise the risk to your tenants?

What is legionella?

Legionella is a bacteria that can form in water when:

1. the temperature is between 20 and 45 degrees Celsius, and
2. certain nutrients are present, e.g. sludge, scale and rust.

It can form in any kind of hot or cold water systems, including water tanks and air conditioning units. If the bacteria is then inhaled via water droplets, it can cause Legionnaire’s disease, a type of pneumonia that can be fatal if it’s left untreated.

What are a landlord’s legal obligations around legionella checks?

According to the Health & Safety Executive (HSE): “The practical and proportionate application of health and safety law to landlords of domestic rental properties is that whilst there is a duty to assess the risk from exposure to Legionella to ensure the safety of their tenants, this does not require an in-depth, detailed assessment.” 

In reality, if your property is occupied and the water system is in regular use, the chance of legionella bacteria forming is very low, so regular checks are unnecessary. The risk is even lower if you have a combination boiler and electric showers.

What does the legionella risk assessment and check involve?

The most important check to make is the temperature of the hot and cold water. You can do this by holding a thermometer under a running tap:

• Hot tap – after one minute, the thermometer should register a minimum of 50 degrees Celsius
• Cold tap – after two minutes, the thermometer should register a maximum of 20 degrees Celsius

For water heaters, a surface temperature probe can be used to check the outgoing water, which should be at least 60 degrees Celsius.

As well as recording water temperatures, the assessment should also include:

• A description of the hot and cold water systems
• Confirmation that the cold water tank is free from scale and rust, etc. and the lid is secure
• Whether there are any water outlets that arent used often – such as guest bathrooms
• The location of all showers
• Ensure that the property isn’t left unoccupied for a long period

Who can make the checks and carry out the risk assessment?

If you’re happy to, you can carry out the legionella risk assessment and checks yourself, or we can organise this for you – more information about Legionella can be found on our blog here.

A professional assessment can cost anything from £50 to £200. Depending on the size of property. If you have a fully managed letting service your agent may have access to preferential rates.