Water safety and legionella records for landlords

You need a risk assessment, not a certificate. For most domestic lets it is short, practical and can be done by the landlord.

4 min read · Updated 21 August 2026

Overview

Landlords have a duty under health and safety law to assess and control the risk of exposure to legionella bacteria in the water systems they are responsible for. For a typical domestic property with a combination boiler and mains fed outlets the risk is low and the assessment is simple. There is no legal requirement for a legionella certificate, and companies selling one for every property are selling more than the law requires.

Why it matters

The duty is often either ignored entirely or over bought. A proportionate written assessment on file satisfies the requirement and costs very little.

Legal requirements

A risk assessment of the water system is required and must be reviewed periodically.
Identified risks must be controlled, and the controls recorded.
There is no statutory legionella certificate for domestic rented property.
Records should be retained and made available on request.

Common mistakes

Buying an expensive certificate for a simple combi boiler flat while never reviewing it.
Ignoring stored water systems, unused outlets and long dead legs in older properties.
Failing to flush a property that stood empty for weeks before a new tenancy.
Not giving tenants any guidance on showerheads and unused taps.

Practical guidance

Complete a short written assessment covering the system type, temperatures, storage and any dead legs.
Flush all outlets after a void and record that you did.
Tell tenants to run unused outlets weekly and to clean showerheads periodically.
Review the assessment after any change to the water system or a long vacancy.

What a simple assessment covers

Identify the system: mains fed combination boiler, or stored hot water with a cylinder and possibly a cold tank. Check hot water reaches a suitable temperature at the outlets and that cold stays cool. Look for redundant pipework, rarely used outlets, showerheads and any water feature. Record the findings, the controls and the review date. For a modern flat this fits on one page.

When to bring in a specialist

Larger properties, HMOs with complex pipework, buildings with cold water storage tanks, communal systems, and any property with vulnerable occupants justify a professional assessment. So does any system with a history of temperature problems. The cost is modest against the consequence, and in licensed HMOs the council may expect a professional document as part of the management arrangements.

Frequently asked questions

Do I need a legionella certificate?

No. The duty is to assess and control risk. A written assessment kept on file is what regulators expect for domestic lets.

Can I do the assessment myself?

For simple domestic systems, yes, provided you understand what you are looking for. Complex or communal systems should be assessed professionally.

How often should it be reviewed?

Review when the system changes, after a long void or at least every couple of years so the record stays current.

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This guide is general information for UK landlords and letting agents, not legal advice. Rules differ across England, Wales, Scotland and Northern Ireland — check your local requirements or take advice before acting.