I am increasingly hearing from agents being told they need to carry out fairly expensive legionella assessments in their rental properties. This is often coming from companies who purport to be experts in this area and offer to provide the service, for a fee of course!

However, is this really necessary. The HSE say not. On their website they do actually provide a fair bit of information about a landlord’s responsibilities and duties.

There is also a neater summary in an FAQ section. This contains the following advice:

In most residential settings, a simple assessment may show that the risks are low and no further action may be necessary. (An example of a typical lower risk situation may be found in a small building (eg housing unit) with small domestic-type water systems, where daily water usage is inevitable and sufficient to turn over the entire system; where cold water is directly from a wholesome mains supply (no stored water tanks); where hot water is fed from instantaneous heaters or low volume water heaters (supplying outlets at 50 °C); and where the only outlets are toilets and wash hand basins).  If the assessment shows the risks are low and are being properly managed, no further action is needed but it is important to review the assessment regularly in case anything changes in the system.

This is a pretty clear statement that there is no real need to do anything in most cases. A full assessment may be needed where a property has risk factors such as hot or cold water storage tanks or has an elderly system. However in a property heated by a modern combi-boiler the risks are extremely low and no detailed assessment is likely to be needed. 

The only other need it to advise tenants to keep showerheads clean and to flush through the system if it has not been used for some time.

For most modern properties Legionella bacteria are a very small risk which should be placed far behind the more important risks of injury by fire, falls and electric shock. Agents and landlords should devote their time and money to working on these more common risks rather than something which is unlikely to affect most properties.