Certificates & safety
What is a legionella risk assessment?
A legionella risk assessment considers the risk from water systems in a rented property. Landlords have a duty to assess and control the risk, though most domestic systems are low risk.
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<a href="https://propertyoptix.co.uk/glossary/legionella-risk-assessment">What is a legionella risk assessment?</a> — diagram by
<a href="https://propertyoptix.co.uk">PropertyOptix</a>
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</figure>It is frequently oversold. For a typical domestic property with a combination boiler and no stored water, the assessment is short and the controls are simple, and an expensive certificate is not what the duty requires.
Risk concentrates where water is stored, where it stagnates, and where it sits at temperatures that suit bacterial growth. Tanks, long runs, little-used outlets and void periods between tenancies are the features that matter.
Void periods are the specific practical control. A property empty for weeks needs flushing before a new tenant moves in, and that is the step most often skipped.
What goes wrong in practice
- An expensive certificate bought where a simple assessment was what the duty required.
- No flushing regime after a void period.
- Stored water systems assessed once and never revisited after changes.