Legionella FAQ for landlords

If you let residential property you have a duty to assess and control the risk from Legionella bacteria in the water system. In Great Britain that duty sits under the Health and Safety at Work etc. Act 1974 and the Control of Substances Hazardous to Health Regulations, with practical detail in the HSE's Approved Code of Practice L8 and guidance HSG274.

For most simple domestic systems the assessment is short and proportionate: understand the system, identify anything that could let water stagnate or sit at warm temperatures, check what you can, and record what you found.

The duty follows control of the premises. A landlord who manages their own lettings holds it directly. Where a managing agent takes on responsibility for maintenance and compliance, the written management agreement should say clearly who carries out and records the assessment.

Whoever does the work, the landlord should hold a copy of the record. Agents managing several landlords normally keep one register with a record per property.

There is no statutory Legionella certificate for a residential letting. What is expected is a risk assessment record: what was assessed, what was found, what controls are in place and when it will be reviewed.

LegionellaWise produces exactly that as a dated, version-stamped report with a public verification reference so a tenant, agent or inspector can confirm it is genuine.

For a simple domestic property, a landlord who understands the system and is competent to make the judgements can carry out the assessment themselves. Complex or higher-risk situations — communal or shared systems, stored hot water in larger buildings, cooling systems, spa pools, vulnerable occupants or anything you are unsure about — should go to a specialist.

Our free suitability check asks a short set of questions and tells you plainly whether self-assessment is appropriate or whether the property should be referred.

There is no fixed statutory interval for a domestic letting. Common practice is to review roughly every two years, and to review sooner whenever something changes.

Trigger a review when the water system is altered, a cylinder or shower is replaced, the property is empty for a period, occupancy changes materially, or a case of Legionnaires' disease is linked to the property.

A useful record covers the water system and how it is heated and stored, a room-by-room list of outlets, the checks you carried out with dates and readings, any photographs or notes supporting them, the findings, the control measures and remedial actions, and the review date.

Assessments made from memory or from a generic template with no property detail are the ones that fail to stand up later.

Keep the current assessment plus previous versions so you can show the history of the property. Because each LegionellaWise report is an immutable snapshot with its own reference, superseded versions stay available rather than being overwritten.

The usual expectations for a domestic system are hot water reaching at least 50°C at the outlet after running, and cold water staying below 20°C after running. Legionella multiplies in the range roughly between 20°C and 45°C, so the aim is to keep water either hot enough or cold enough.

Take readings after flushing the outlet so you are measuring the supply rather than water that has been sitting in the tap body.

A blended outlet fed through a thermostatic mixing valve is designed to deliver water below scalding temperature, so a low reading at that tap is not evidence of a hot water failure. Record that the outlet is blended, and where possible check the hot supply upstream of the valve instead.

TMVs also need to be kept in working order, so note their presence and condition in the record.

Routine sampling is not normally expected for a simple domestic system. Sampling is a specialist step, typically prompted by a specific concern, an outbreak investigation or a higher-risk system, and should be arranged through a competent provider.

Give practical, plain-language advice: run taps and showers after any period away, keep shower heads and hoses clean and free of scale, do not reduce the hot water thermostat below the design temperature, report any problem with the hot or cold water, and flush any little-used outlet regularly.

Noting that you provided this advice, and when, is part of a complete record.

Water left standing is the main risk in a void. Flush all outlets regularly while the property is empty, and flush thoroughly before a new tenant moves in, including showers where aerosol is generated.

Record the flushing you carried out and the dates. A void is also one of the events that should prompt a review of the assessment.

A reading outside the expected range becomes a finding. You record it, decide the remedial action — for example adjusting the cylinder thermostat, insulating or rerouting pipework, servicing or replacing a mixing valve, or removing a redundant outlet — carry it out, and re-check.

A failing outlet is never cancelled out by a passing one elsewhere in the property. Each outlet stands on its own, and the report shows the finding and the action taken against it.

Yes, and that is often the honest position. The report records the finding, the action required and its status, so the evidence trail shows what was found and what is being done. Actions completed later are tracked against the property with their own dated evidence.

Commissioning a third-party assessor for a domestic letting typically costs considerably more than doing a proportionate self-assessment. LegionellaWise is £19.99 for a single report, with annual plans for landlords, portfolios and agents covering more properties and adding review reminders.

Keep one register with every property, its current assessment, its review date and any open remedial actions, then work from reminders rather than memory. LegionellaWise sends review reminders ahead of each due date and shows outstanding actions in one place.

14-day money-back guarantee on your first paid report. If you're not satisfied, contact us within 14 days of purchase for a full refund. This does not affect your statutory rights.

One refund per customer applies, and it covers your first paid purchase on the account. Ask for it from your account email address within 14 days of payment, by emailing support@legionellawise.com or using the contact page. Refunds go back to the original payment method, and the credits or property slots from that purchase are withdrawn. The full terms are on the terms of service page.

Yes. A full sample report is free to view or download from the homepage and the pricing page, with no account needed. It is produced from a fictional property and assessment and is watermarked as a sample, so you can see every section a paid report contains — outcome, outlets, temperatures, findings, actions, evidence and declaration.