Water stagnation in a vacant rental: a landlord's reoccupation plan

When a rented home has stood empty, the water that sat unused in its pipes is a changed risk. Before a new tenant moves in, assess the system proportionately, flush through fresh water, deal with any legionella risk the assessment identifies, and record what you did. For most simple homes this is quick and low cost; the point is to do it and evidence it.

What has happened

A property has been void for weeks or months, and hot and cold water has sat in the pipes, cylinder and any showerheads or little-used outlets. Stagnation, together with water sitting at warm-ish temperatures, is exactly the condition in which legionella bacteria can multiply. HSE is clear that landlords who provide residential accommodation have a duty to assess and control the risk of exposure to legionella, and that for most domestic systems the controls are simple and proportionate rather than a complex regime.

Immediate actions (before reoccupation)

Carry out or revisit a legionella risk assessment for the property, taking account of how long it has been empty and the type of system. Flush all outlets to draw fresh mains water through the system: run taps and showers, and do not forget rarely used outlets. Where the assessment indicates, remove and clean or descale showerheads. Confirm the hot water system heats water properly and that cold water runs cold. For a long void, a complex system, or an incoming occupant who is more vulnerable to infection, take competent advice and consider whether disinfection is warranted before handover.

What not to do

Do not skip the check because "it's only a flat", and do not assume a quick tap-run at the front door clears the whole system. Do not leave showerheads full of stagnant water for the new tenant's first shower. Do not over-engineer a simple low-risk home into an unnecessary specialist chlorination, but equally do not ignore a long void or an unusual system. And do not rely on memory: if it is not recorded, it is hard to show the duty was met.

Who is responsible

The landlord (or managing agent under the agreement) holds the duty to assess and control legionella risk. A competent person carries out the assessment; for simple systems the landlord or agent may be competent to do a basic assessment themselves, while complex or higher-risk systems need specialist input. The incoming tenant should be given any simple advice relevant to keeping the risk low, such as flushing outlets after their own future absences.

Evidence and records

Record the risk assessment, the length of the void, the flushing and cleaning carried out, any temperatures checked, any specialist involvement and the date the property was confirmed ready. Keep this with the property's compliance file so the control is demonstrable and the next void can follow the same steps.

Escalation

Escalate to a competent water-hygiene specialist where the assessment identifies higher risk, the system is complex (large or stored hot water, unusual pipework, a communal supply), the void was long, or an incoming occupant is more vulnerable. Escalate promptly if anyone develops symptoms that could relate to the water supply. For communal water systems serving a block, coordinate with the building's wider water-safety arrangements rather than treating one flat in isolation.

Prevention

Build void management into your re-let process so every empty property is flushed and assessed before handover, keep the legionella assessment under periodic review, and log expected re-let checks alongside gas, electrical and alarm items. A standard void checklist turns this from an easily forgotten task into a routine, evidenced step.

Where Complys can help

Complys can hold the property's legionella risk assessment, void checklist and re-let evidence alongside its other safety records, and remind you to complete water-safety steps before a new tenancy. It does not carry out water-hygiene assessments or sampling; a competent person does that. Ask the Complys team to show how the property record and re-let checklist fit your void process.