Do landlords need legionella testing?
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Key points
- Landlords have the same legionella duty as any duty holder: assess the risk in the let property and control it. That duty is real law, under HSWA, COSHH and ACOP L8.
- Routine laboratory testing is not required for most domestic lets. HSE's own guidance says simple residential systems generally do not need sampling.
- Combi boilers and electric showers are lower risk because there is no stored water; systems with tanks and cylinders deserve more attention.
- Void periods are the real danger point: flush the whole system through before a new tenancy starts.
- Keep simple written records of the assessment and what you did. A laboratory test is not a certificate and never replaces them.
If you let out a house or flat in the UK, you have a legal duty to assess and control the risk from legionella in the property's water system, but you almost certainly do not need to send water samples to a laboratory. That pairing surprises people in both directions: landlords who assumed legionella was someone else's problem learn the duty is theirs, and landlords braced for an expensive annual testing regime learn that HSE's own guidance says most domestic systems do not need sampling at all. Both halves matter.
The duty you actually hold
As a landlord you are a duty holder under the Health and Safety at Work etc. Act 1974 and the COSHH Regulations, applied to water systems through ACOP L8. The duty is to assess the risk from legionella in the property and to control it. Our guide on who is responsible for legionella in rented property sets out how the duty sits between landlord, agent and tenant. The assessment for a simple flat need not be elaborate, but it must exist and it must be real: a look at the water system, an honest view of the risks, and a note of the controls.
Why most domestic lets do not need sampling
Legionella risk scales with stored, warm, stagnant water. A modern flat with a combi boiler heats water on demand, so there is no stored hot water to colonise, and if the cold feed comes straight from the mains there is no storage tank either. Add electric showers rather than mixer showers fed from a cylinder, and the main growth conditions are largely absent. HSE's guidance for landlords reflects exactly this: for simple residential systems, the risk is usually managed by basic controls, and routine sampling is not needed.
The properties that deserve more thought are the ones with storage: a cold water tank in the loft, a hot water cylinder, long pipe runs, or shared plant in a house in multiple occupation. There the assessment has more to weigh, and sampling may have a place in what it concludes.
What to actually do, in practice
- Assess the risk and write it down: the system type, the risks found, the controls you will run. A template or the risk assessment tool structures this.
- Keep hot water hot and cold water cold. Where there is a cylinder, stored water should be at 60°C and hot outlets should reach 50°C within a minute; cold should stay below 20°C. The legionella temperature checker tests your readings against the thresholds.
- Flush at voids. The highest-risk moment in a rental property is the gap between tenancies, when water stands still in every branch. Before a new tenant moves in, run every outlet through, hot and cold, paying particular attention to showers. Our guide to flushing little-used outlets covers the method.
- Ask tenants to do their part: clean or descale shower heads, report taps that will not get hot, and tell you before long absences.
- Review on change: a new boiler, a bathroom refit, or a long void are all reasons to look at the assessment again.
Free legionella risk assessment template
A structured Word document following the five-step approach in ACOP L8. Covers risk identification, written scheme, monitoring, and records. If it isn't written down, you can't evidence it.
Follows ACoP L8 and HSG274 Part 2. Free. No spam.
When a landlord should consider sampling
Sampling earns its cost in specific circumstances: an HMO with shared tanks and cylinders where the assessment cannot rule the risk out by simpler means; a property with a long void behind it and vulnerable incoming tenants; a system fault that will not resolve, such as hot water that never reaches temperature; or after any link to a case of Legionnaires' disease. When you do sample, use a UKAS-accredited laboratory with legionella on its scope: our testing laboratory directory compares them on method, turnaround and published price, and how to test for legionella walks through the process.
Beware the certificate that does not exist
Some contractors market an annual “legionella test” or “legionella certificate” to landlords as though it were a legal requirement like a gas safety certificate. It is not. There is no legionella certificate in UK law, and HSE has cautioned landlords specifically about being sold unnecessary testing. What protects you, and your tenants, is the assessment, the controls, and the records that show both happened, kept for at least five years in a log book. That paperwork is cheaper than an annual test and it is what the duty actually asks for.
For a landlord, the honest package is an assessment, hot water kept hot, a full flush before each new tenancy, and a written record. Sampling is for the properties and moments where the assessment says simpler controls cannot answer the question.
Free legionella risk assessment template
A structured Word document following the five-step approach in ACOP L8. Covers risk identification, written scheme, monitoring, and records. If it isn't written down, you can't evidence it.
Follows ACoP L8 and HSG274 Part 2. Free. No spam.
Frequently asked questions
Do landlords need a legionella test certificate?
No. There is no legionella test certificate in UK law, and no document a laboratory can issue that certifies a let property as safe or compliant. What a landlord needs is a record that the risk was assessed and the controls carried out: the risk assessment, notes of any flushing and temperature checks, and any laboratory results where sampling was actually done. A laboratory report is a record of one sample on one day; it records, it never certifies.
How often should landlords test for legionella?
For most domestic lets, not at all in the routine sense. HSE's position is that simple residential water systems generally do not need sampling, because the risk is managed by straightforward controls: hot water stored and delivered hot, cold kept cold, outlets flushed before a new tenancy after any void period. Sampling becomes worth considering where the system is more complex, for example a house in multiple occupation with shared stored water, or where the assessment cannot rule the risk out by simpler means.
Can the tenant do the legionella checks?
Tenants can reasonably be asked to do the simple things within their control, such as cleaning shower heads, reporting temperature problems, and telling you if taps are not getting hot, and many landlords set this out in the tenancy information. But the legal duty stays with the landlord: it cannot be delegated away, and the risk assessment and its review remain yours. Treat tenant cooperation as one control among several, not as the compliance itself.
Who pays for legionella testing in a rented property?
Where sampling is genuinely needed, it is a cost of meeting the landlord's duty to assess and control risk, so it falls to the landlord in the ordinary case. The more important point is not to pay for testing you do not need: HSE has specifically cautioned landlords about being sold routine sampling for simple domestic systems where the risk assessment does not call for it.
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