Legionella risk assessments in 2026: what every landlord must do
Legionella is the one health and safety duty almost every self-managing landlord has heard of and almost none has actually documented. Unlike gas safety and EICR checks, there is no annual certificate to renew and no engineer's report to file, so it is easy to assume the duty does not really apply to an ordinary let with a combi boiler and two taps. It does. The Health and Safety Executive is explicit that landlords carry a legal duty of care to assess and control the risk of legionella in a property's water system - and for most rented homes in England, meeting it is far simpler than it sounds, sitting neatly alongside the rest of your day-one compliance checklist.
What the law actually requires
The duty comes from section 3 of the Health and Safety at Work etc. Act 1974, which extends a landlord's responsibilities to tenant safety, backed by the Control of Substances Hazardous to Health Regulations (COSHH) and the Approved Code of Practice known as L8. Together they require you to assess the risk of exposure to legionella bacteria and put in place reasonable, proportionate control measures. Crucially, HSE's own guidance says this does not need to be an in-depth technical assessment for a typical rented home - a simple, common-sense review is enough, and most residential lettings turn out to be low risk.
| Property type | What is typically needed | Who assesses it |
|---|---|---|
| Single let, combi boiler or electric shower, no stored tank | A simple assessment confirming there is no stored water - usually concludes low risk | You, the landlord - no training or accreditation required |
| Single let with a cold water tank or hot water cylinder | Checks on tank lids, insulation and stored water temperature (60°C at the cylinder) | You, or a professional if you would rather not |
| HMO or block with a shared water system | A fuller assessment covering the whole system, with ongoing monitoring | Usually a specialist - landlord and managing agent must cooperate on shared risks |
Doing your own risk assessment
For a straightforward single let, you do not need to hire anyone. Work through the basics: confirm whether the property has a stored cold water tank or hot water cylinder, or whether it runs on a combi boiler or instantaneous electric shower (both lower the risk significantly, since there is no standing water to breed bacteria). If there is a tank, check the lid fits tightly to keep out debris and insects, and that the hot water cylinder is set to store water at 60°C. Look for any redundant pipework - a length of pipe that no longer leads anywhere - and have it removed, since stagnant water sitting in a dead leg is a classic risk factor. Tell your tenant not to alter the cylinder thermostat, to clean and descale showerheads regularly, and to report it immediately if the hot water is not heating properly.
You are not always legally required to write any of this down - that specific recording duty falls on employers with five or more staff, not most individual landlords - but keeping a dated note of what you checked, and when, is the simplest way to show you met your duty if it is ever questioned. Many landlords fold the check into a visit they are already making, such as the annual gas safety inspection, rather than treating it as a separate job.
What happens if you get it wrong
HSE and local authorities do not routinely inspect domestic properties for legionella compliance, so this is not a duty that gets policed the way a missing smoke alarm does. The exposure comes if a tenant contracts Legionnaires' disease and it is traced back to the property's water system - at that point you would need to demonstrate to a court that you had assessed and controlled the risk. A conviction under the Health and Safety at Work Act can carry an unlimited fine and, in the most serious cases involving real harm, a prison sentence. There is no such thing as a "legionella certificate", and testing water samples in a laboratory is rarely needed for an ordinary home - do not confuse it with the simple temperature checks described above, which are what actually demonstrates control.
Keep every safety date in one place
The Complete Landlord Pack includes a Landlord Compliance Calendar that sits alongside your gas safety, EICR and EPC dates - add your legionella check to it once and you will always know when it is due again.
See the packs →Frequently asked questions
Do I need to hire a professional to do a legionella risk assessment? No. For a typical single let, HSE guidance is clear that landlords can carry out their own assessment without any special training or accreditation. You can arrange for a professional to do it instead if you would rather not, particularly for larger or shared systems.
How often do I need to review it? The law does not set a fixed interval. Review it whenever something changes - a new tenant, an extended void period, or work done to the water system - and it is common practice to check it again at the same time as your annual gas safety visit.
Does having a combi boiler mean I do not need to worry about legionella? It significantly lowers the risk, because there is no stored water sitting at the temperatures legionella needs to grow, but it does not remove the underlying duty to think about it and be able to show you have.
What happens if I never do one and a tenant later gets ill? Enforcement is not proactive, but if Legionnaires' disease is traced back to your property, you would need to show a court that you had assessed and controlled the risk. That can mean prosecution under health and safety law, with fines that are not capped and, in the gravest cases, imprisonment.
This guide is general information for landlords in England, not legal advice for your specific circumstances. Check current guidance at hse.gov.uk before relying on it for a specific property.