The assessment should reflect the actual hot and cold water system and how the property is occupied. Low-use outlets, stored water and long void periods can change the risk.
Understand the water system
Identify stored water, little-used outlets, long pipe runs and periods when the home is empty. The assessment should fit the actual system and use.
- Record who is responsible for assessing and managing the risk and whether they have the competence needed. Use a specialist where the system or risk is beyond their knowledge.
- Check whether hot and cold water arrangements, storage and infrequently used outlets create avoidable risks. Do not disturb or adjust unfamiliar equipment without competent advice.
- Keep the assessment and the controls it recommends. There is no universal requirement to buy a routine landlord legionella certificate.
Manage ordinary use and vacancy
Use the assessment to set appropriate controls rather than applying an arbitrary testing package to every home.
- Explain any sensible occupant actions identified by the assessment, including care of outlets or reporting hot-water faults.
- Before reoccupation after a vacancy, review stagnation and the recommended flushing or other controls. Record what was done.
- Ensure repairs or replacement tanks and pipework do not undermine the controls. Ask the installer to identify relevant changes.
Review after a material change
The water system may need reassessment even when the tenancy itself has not changed.
- Review after alterations, a change of use, a prolonged empty period or a problem suggesting the controls are ineffective.
- Keep contractors' findings and any measurements with the assessment, including the reason for choosing or not choosing sampling.
- Escalate a suspected health incident or significant system failure to appropriate professional advice. Do not diagnose illness or declare water safe from a visual check.
Example: a flat has been empty for months
A fictional flat is relet after a long refurbishment. Review the water risk assessment and complete the recommended preoccupation controls before handover. An old certificate from a previous tenancy does not describe the current period of stagnation.
What to do
- Identify the system and whether competent help is needed.
- Record practical controls and information for occupants.
- Review after changes, prolonged vacancy or identified problems.
Evidence to keep
- Risk assessment and control measures
- System changes and flushing or maintenance records
Sources and guidance
- Legionella and landlords’ responsibilitiesHealth and Safety Executive · checked 20 October 2026