Legionella Logbook for Landlords: What to Record Monthly

Keeping on top of Legionella control in a rental property goes far beyond simply having a risk assessment document tucked away. It requires ongoing attention through regular checks and thorough record-keeping to demonstrate that water safety is actively managed throughout the entire tenancy. This continuous approach ensures that potential risks are identified and addressed promptly, rather than relying solely on a snapshot taken during a one-off inspection. Clear, up-to-date records provide evidence that you are consistently monitoring water systems, which is crucial for protecting tenants’ health and meeting your legal responsibilities as a landlord. For example, noting monthly flushing of seldom-used outlets or temperature checks on hot water can help prevent the conditions that allow Legionella bacteria to thrive.

This proactive management is especially important in properties with long void periods, shared accommodations like HMOs, or those with stored hot water cylinders where water stagnation is more likely.

Purpose of a legionella logbook for landlords

A legionella logbook is a simple record of what has been checked, when it was done and what action you took. It supports your risk assessment by showing that the control measures it recommends are actually being followed.

For most landlords and agents, a straightforward paper or digital log is enough. It does not need to be complicated, but it must be consistent, legible and kept up to date so you can refer back if there is ever a query or incident.

Core information your water hygiene logbook should hold

Your logbook should make it easy for anyone involved with the property to see what system is in place and who is responsible for checks. Setting it up properly at the start saves confusion later, especially if agents, contractors and landlords all share duties.

• Property details: full address, flat number and any relevant notes (for example, top-floor flat with cold water storage tank).

• Responsible person: the main contact for legionella controls, with name, role (landlord/agent), email and phone number.

• System overview: tick-box style summary of combi boiler, stored hot water cylinder, cold water storage tank and any point-of-use heaters.

• Outlet list: each tap, shower and other outlet, clearly named and located so checks can be repeated in the same way each time.

Once this core information is in place, the rest of the logbook is mainly about regular entries that show you are carrying out practical control measures month by month.

Monthly records to keep in a legionella logbook

Monthly entries are usually brief, but they build a clear picture over time. If you work with a managing agent, agree in writing who will complete each section so nothing is missed.

Flushing infrequently used outlets

Outlets that are rarely used can allow water to stagnate, which may increase legionella risk. Your logbook should list these outlets and show that they are flushed regularly, particularly during void periods.

For each flushing visit, record the date, outlet name, how long it was flushed for and your initials. If a tenant is responsible for flushing a little-used bathroom, give them simple instructions and ask them to sign or confirm in writing when it has been done.

Showerhead cleaning and descaling

Showers create fine water droplets, so they deserve specific attention. Showerheads and hoses should be cleaned and descaled at planned intervals, often quarterly, but you can note these checks alongside your monthly pages so they are not forgotten.

Record which shower was cleaned, the method used (for example, descaling solution, physical clean) and any issues such as damaged hoses or poor spray pattern. If you replace a showerhead, make a note of the date and product type.

Temperature checks where appropriate

For some systems, especially those with stored hot water, temperature checks are a useful control. If your professional legionella risk assessment recommends temperature monitoring, your logbook gives you a place to note readings.

Typical entries include cylinder flow temperature, return temperature where relevant and outlet temperatures at key taps. Always follow the guidance from your competent assessor, and record any readings that fall outside their recommended range along with what action you took.

Vacancy periods and void management

Empty properties need special attention because water can sit in pipework for long periods. Your logbook should clearly show start and end dates for void periods, along with any measures taken, such as full-system flushing before re-letting.

When a tenant moves out, record the date, note that the system was flushed through and showers run, and log any additional cleaning or checks. On re-occupation, it is helpful to show that taps and showers were run again and that tanks or cylinders were visually inspected where safe to do so.

Simple legionella logbook template you can adapt

You can keep your records in a folder or spreadsheet. Below is a plain text layout you can copy and tailor to each property.

Property details
Address: _______________________________
Unit / Flat: ___________________________
Type: House / Flat / HMO / Student let
System summary: Combi / Cylinder / Cold water tank (circle)

Responsible person
Name: _________________________________
Role: Landlord / Agent / Other
Contact: ______________________________

Outlet list
1. Kitchen sink tap
2. Bathroom basin tap
3. Bath tap
4. Shower 1 (main bathroom)
5. WC hand basin (ground floor)
Add others as needed

Monthly log page
Month / Year: _________________________

Flushing of infrequently used outlets
Date | Outlet | Duration (mins) | Initials
____ | ______ | _______________ | _______
____ | ______ | _______________ | _______

Showerhead cleaning / descaling
Date | Location | Action | Initials
____ | ________ | ______ | _______

Temperature checks (if applicable)
Date | Location / Cylinder | Temp (°C) | Action needed?
____ | ___________________ | _________ | ______________

Void periods and actions
Void start: ___________ Void end: ___________
Flushing / cleaning carried out: Yes / No
Notes: ______________________________________

Situations where good records matter most

All rentals benefit from clear documentation, but some property types carry a higher expectation of structured water hygiene records. In these cases, a simple logbook can be especially helpful.

Student lets and HMOs often have multiple occupants, shared bathrooms and periods when some rooms are unused. Regularly recorded flushing and cleaning helps demonstrate that you have considered these patterns and put controls in place.

Properties with stored hot water cylinders or cold water tanks also benefit from careful records of temperatures, visual checks and any maintenance. This is particularly relevant in older buildings and larger HMOs where systems are more complex.

Working alongside professional legionella services

A logbook supports, but does not replace, a professional legionella risk assessment. The assessment identifies risks and control measures, while the logbook shows that those measures are being implemented between visits.

If your records highlight anything unusual, such as persistently low hot water temperatures, visible debris in tanks or tenants reporting unusual smells or discolouration, you should seek advice from a competent person rather than trying to diagnose issues yourself.

For specialist help, you can arrange legionella risk assessments and water hygiene support visits through providers such as KSM PLUMBING LTD's Legionnaires water services. It is also helpful to remember that legionella control sits alongside, but is separate from, gas safety checks such as your annual CP12; for more on that area, you can refer to KSM's CP12 information.

Next steps for landlords and agents

Set up a basic legionella logbook for each property, agree who will complete it and keep it with your other compliance documents. Combine it with a current professional risk assessment and clear tenant guidance so everyone understands their role.

If you would like support putting practical controls in place, or need an up-to-date Legionella risk assessment, you can book a visit with KSM PLUMBING LTD on 07704373410 for straightforward, professional help.