Legionella risk assessments: the quiet duty that still catches landlords out

Ask ten landlords what they worry about and you will hear gas, electrics, deposits, and the tenant who pays six days late. Legionella sits in a different pile: the duty you half remember from an agent's onboarding email, then forget until someone asks for "the certificate".

Here is the first correction. For most ordinary houses and flats, you are not hunting for a framed certificate. You need a risk assessment that matches the water system you actually have, and you need to do the simple control measures it points to. The Health and Safety Executive has been clear about this for years. The letting market still talks as if a plumber prints a magic document once a decade.

Why landlords have this duty at all

Legionnaires' disease is a pneumonia caused by bacteria that like lukewarm, stagnant water. Showers, unused en suites, and stored hot water tanks are the usual story in housing. You control water systems in a property you let. That puts a health and safety duty on you, even if you never set foot in the place from one quarter to the next.

Fatal cases in rented homes are rare. Enforcement and civil claims are not a daily event either. The practical risk for most small landlords is different: you cannot prove you thought about it. After an incident, "I didn't know" is a rotten sentence to say out loud.

What a decent assessment looks like

Walk the property, or get someone competent to do it. Note where water is stored, the temperature of the cylinder if you have one, little-used outlets, showers, outdoor taps, and any dead legs in the pipework. Ask how long rooms sit empty. A student house in summer is not the same as a family home with daily baths.

Write the findings in ordinary language. Date it. Keep it with the gas record and the EICR, not in the notes app on your phone. If the assessment says the risk is low and the controls are flushing unused showers and keeping stored hot water hot enough, do those things. Setting a cylinder so the stored water reaches 60°C is the textbook control. Outlets should then run hot enough to be useful without scalding people, which is why mixing valves exist.

The jobs people skip

• Flushing taps and showers in spare rooms after a void.
• Descale shower heads that look like they belong in a museum.
• Telling the tenant, politely, not to leave an ensuite unused for months.
• Reviewing the assessment after a new boiler, a loft conversion, or a change from one tenant to five.

HMO stock and buildings with communal tanks deserve more attention. If you have a plant room you do not understand, pay someone who does. Competency is the legal idea. A two-page template copied from a forum is not competency if the building has a calorifier the size of a van.

How often, and who can do it

There is no single statutory anniversary like the gas safety year. Review when something changes, and on a rhythm that matches the risk. Many landlords look at it annually because that is when the rest of the file gets opened. That is a habit, not a magic number, and it is still better than never.

You can often do a simple domestic assessment yourself if you understand the system. Managing agents like a third party because it is easier to show a client. Either route is fine if the document is real. A PDF titled "Legionella cert 2019" with the wrong address is not.

Where this sits with everything else

Water safety lives next to damp, mould, and the repair clock. A tenant who says the shower has not worked in weeks is also telling you the outlet is stagnant. Log the report, get it fixed, and note that you flushed the system when the property came back into use.

Tenlord will not take the sample for you. It will remind you that the assessment exists, store the file, and keep the conversation with the tenant in one thread instead of four chat groups. For a duty this easy to forget, that is most of the battle.