Legionella! What is all the fuss?

Legionella is a pneumonia style bug caused from being in contact with contaminated water droplets – primarily breathed in.

The regulations, in their most basic form, state that the water system must be safe to use and that every property let out needs to be assessed.

In order to do this the landlord or agent needs to know the plumbing system and what heating appliances are in the building and have a very clear working knowledge of where the pipes run.

A modern house with a new gas boiler is very simple to understand with a straightforward and limited amount of pipework. By comparison to an older property, especially one which has over the years been turned into flats; where there can be a myriad of pipes, some no longer in use or just dead legs.


To do a basic assessment, the water system should be able to be mapped out, including any water tanks as this will highlight any potential problem areas. There also needs to be a test of the hot water temperature at source and at the point of delivery (tap) – ideally the water should be stored at a constant 60 degrees; legionella thrives between 20 and 45 degrees.

The unclear issue is that the regulations stipulate that the assessment must be done by a “competent person” and the ACOP (A Code of Practice) Water Regulations clearly state that a competent person is one who has passed a Legionella exam!! The HSE (Health & Safety Executive) do not recognise a legionella certificate and under current Health & Safety law it is not a requirement to obtain one.

Being safe is a very grey terminology and if anything does go wrong at some time and a tenant contracts legionella (by breathing in the water droplets/spray) which is spotted by doctor then the landlord or agent, as the responsible person, will be facing a substantial fine up to £20k or worse!

This regulation does not appear to be policed at present but as the government digs ever deeper into the PRS (Private Rental Sector) and seeks to make homes fit and safe for tenants to live in, then rest assured it will become a legal requirement, just as the electrical checks will soon be. The simple answer is make sure the tenant has guidance and do get it tested, be safe and compliant!