What the law says
If you rent out a home in England, section 3 of the Health and Safety at Work etc. Act 1974 and the Control of Substances Hazardous to Health Regulations (COSHH) mean you must make sure tenants are not exposed to health risks from the water system, including legionella bacteria.
The Health and Safety Executive (HSE) says that duty includes a proportionate legionella risk assessment. For most ordinary houses and flats the assessment is simple. It does not require a formal certificate, laboratory testing, or a specialist visit unless you are not competent to do it yourself or the system is more complex.
Deadlines at a glance
| What | When |
|---|---|
| Assess the risk from the hot and cold water system | Before letting, and keep it under review |
| Review the assessment | When the system changes, or periodically if nothing has changed |
| Flush unused outlets after a void | Before the next tenant moves in |
| Store hot water | Around 60°C in the cylinder; keep cold water cold and moving |
| A 'legionella test certificate' | Not required for a typical domestic let |
What a simple assessment covers
HSE guidance for landlords is that you identify where water is stored or can stagnate, whether temperatures sit in the 20–45°C range where legionella can grow, and whether droplets can be produced (showers are the usual concern).
For a typical domestic system, write down:
- who is responsible for the water system (usually you, or your managing agent if the contract says so);
- a short description of the system (combi boiler or hot water cylinder, cold tank if any, showers);
- the main risks you found and the controls you keep in place;
- when you will review the assessment.
A short written note is enough for most single lets. Keep it with the property's other records. HSE does not ask for a stamped certificate, and buying one does not replace a proper look at the system.
Simple controls that keep the risk low
- Flush the whole system, including showers and unused taps, before a new tenancy starts or after a long void.
- Store hot water at about 60°C in the cylinder. Keep cold water cold and moving; fit a tight-fitting lid on any cold water tank.
- Remove redundant pipework (dead legs) where you can.
- Ask tenants to clean and descale shower heads regularly, and tell them about the risk in plain language.
- Inspect the system when you already visit for gas safety or other maintenance if access is hard during the tenancy.
Do you need a professional or a lab test?
Most landlords can do the assessment themselves if they understand the system and the simple controls above. If you are not confident, or the property has a more complex water system (large shared plant, spa baths, cooling equipment), appoint someone competent to assess it for you.
Routine sampling for legionella is not usually needed in domestic hot and cold water systems. Temperature checks are the usual way to confirm the system stays under control. Don't confuse a paid 'legionella certificate' with the legal duty: the duty is to assess and control the risk.
Penalties and evidence
Failing to manage legionella risk can lead to HSE enforcement and, in serious cases, prosecution under health and safety law. Councils can also ask for evidence of how you manage the water system when they inspect or license a property.
There is no fixed statutory expiry date for a domestic assessment. Still keep a dated note of what you checked, the controls you use, and the next review date. That is the evidence a council, agent or insurer usually wants to see.
What changed in 2026
The legionella duty itself did not change in 2026. What changed is how closely landlords' safety records are scrutinised: the written statement of terms from 1 May 2026, stronger council investigation powers, and the private rented sector database opening region by region from 15 December 2026. A dated assessment and review note sit next to your gas, EICR and alarm records.
How LetRecord helps
LetRecord adds a legionella review row to every property. Set the next review date, upload the assessment if you have one, and get a reminder before that date with your other deadlines. It is marked as recommended guidance rather than a fixed statutory expiry, matching HSE's approach.
See the duties for a property
Enter a postcode and LetRecord lists the safety and registration duties for that address, including a place to track your legionella review.
Common questions
Do landlords need a legionella certificate?
No. HSE does not require a certificate or routine lab testing for a typical domestic let. You must assess and control the risk, which is usually a short written check you can do yourself.
How often should I review a legionella risk assessment?
There is no fixed annual or two-year rule. Review it when the water system changes, after major works, or periodically if nothing has changed. Many landlords set a yearly reminder so it is not forgotten.
Does a combi boiler need a legionella assessment?
Yes. Every rented home's water system needs a proportionate assessment, including homes with a combi boiler and no stored hot water. The risks are often low, but you still need to consider stagnation, showers and void periods.
Who is responsible if I use a letting agent?
The duty sits with whoever has control of the premises and water system. Your management agreement should say who assesses and maintains it. If the contract is silent, the landlord usually remains responsible.
Do I have to tell tenants about legionella?
Yes. HSE expects you to tell tenants about the risk and any actions they should take, such as cleaning shower heads and running taps after a holiday.
Official sources
This guide explains the rules in general terms and is not legal advice.
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