What goes on a legionella flushing log sheet?
On this page
Key points
- A flushing log sheet records date, outlet, location, temperature reached, and initials for every weekly flush of a little-used outlet.
- Give each outlet a short code (LU-01, LU-02...) so the log line matches the flushing schedule named in the written scheme of control.
- Flush until the temperature stabilises and record the figure you actually reached: hot to at least 50°C, cold below 20°C.
- Keep the sheets for at least five years. Paper and electronic records are equally acceptable if they can be produced on request.
- An unrecorded flush cannot be evidenced. The sheet is the proof the control happened, not a formality around it.
A legionella flushing log sheet is the running record of your weekly flush of little-used outlets: one line per flush, showing the date, the outlet, the temperature the water reached, and who did it. Below is a sheet layout you can copy into a document and print, plus the reasoning behind each column. If you would rather not maintain paper, our log book tool records the same entries in your browser, exports them to CSV, and prints a blank sheet for the plant room wall.
The sheet itself
The layout below is the whole sheet: a header block to identify the premises and period, then one row per flush. Two worked example rows show what a completed line looks like; the blank rows are the sheet itself.
| Date | Outlet ID | Location | Temp reached | Initials | Notes |
|---|---|---|---|---|---|
| 13/07/2026 | LU-01 | Guest bathroom basin, 1st floor | 51.8°C hot | JP | Ran 90 seconds to temperature |
| 13/07/2026 | LU-02 | Outside tap, rear yard | 14.2°C cold | JP | — |
Six columns, no more. Anything more elaborate tends to go unfilled, and an elaborate sheet with gaps is worse evidence than a simple sheet completed every week.
Why each column earns its place
Outlet ID and location. Give every little-used outlet a short code, LU-01, LU-02 and so on, fixed in the flushing schedule in your written scheme of control. The code keeps each log line unambiguous: "the tap" is not evidence; "LU-01, guest bathroom basin" is. The scheme names the outlets; the sheet proves they were flushed.
Temperature reached. The flush is finished when the temperature stabilises, not after a guessed number of minutes, and the figure you record is the proof. On the hot side that means at least 50°C (55°C in healthcare); on the cold side, below 20°C. Recording the number matters because it also catches a system that is drifting: a hot outlet that tops out at 44°C is a finding to act on, not a tick. Our guide on how long to run taps when flushing explains the to-temperature method, and the temperature checker helps you read the figures.
Initials. The flush has to be attributable. Initials link the line to a named person on the rota, which is what an inspector testing the record will look for.
Paper or electronic: both are acceptable
ACOP L8 accepts paper and electronic records equally. Paper earns its keep in a plant room: it is always to hand, it cannot be edited after the fact without leaving marks, and it survives a power cut. Its weaknesses are loss and retrieval, so file completed sheets somewhere dry and findable rather than leaving a year's worth on a hook.
An electronic log makes the archiving and retrieval easy. Our log book tool stores each entry in your own browser with no account and nothing uploaded, exports the whole log to CSV when you need to file or share it, and prints either the completed log or a blank sheet. Many duty holders run a hybrid: paper by the outlets for the current month, scanned or exported into an archive at the end of it. Whichever you choose, keep the records for at least five years.
Free legionella risk assessment template
A structured Word document following the five-step approach in ACOP L8. Covers risk identification, written scheme, monitoring, and records. If it isn't written down, you can't evidence it.
Follows ACoP L8 and HSG274 Part 2. Free. No spam.
Where the sheet sits in the system
The sheet is the last link in a chain. The risk assessment identifies the little-used outlets, the written scheme of control puts them on a weekly flushing frequency, and the log sheet records each flush as it happens. If any link is missing the chain fails: outlets not identified never get flushed, and flushes not recorded cannot be evidenced. The full regime, what counts as little-used, how to flush gently to limit aerosol, and what to do after a shutdown, is set out in flushing little-used outlets, and the sheet slots into the wider calendar in the monitoring schedule template.
Code every little-used outlet, flush it weekly to temperature, and write the line the moment you finish. The sheet is not the paperwork around the control; on paper, it is the control.
What the sheet cannot do
A completed sheet records that water was run through an outlet and reached a temperature. It does not certify that the system is safe, and it is no substitute for fixing what the figures reveal: an outlet that will not reach temperature, a branch that takes minutes to draw through, a finding that belongs back in the risk assessment. It records, it never certifies. Used honestly, though, a year of weekly lines is exactly the evidence a duty holder needs when someone asks how a known risk was controlled.
Free legionella risk assessment template
A structured Word document following the five-step approach in ACOP L8. Covers risk identification, written scheme, monitoring, and records. If it isn't written down, you can't evidence it.
Follows ACoP L8 and HSG274 Part 2. Free. No spam.
Frequently asked questions
What should a legionella flushing log sheet include?
Each entry needs the date, an identifier for the outlet, its location, the temperature reached when the flush finished, and the initials of the person who did it, with a notes column for anything unusual. Give every little-used outlet a short code such as LU-01 so the log line is unambiguous and matches the flushing schedule in the written scheme of control. A sheet with those columns, completed every week, is the evidence that the flushing regime actually happened.
How often should outlets be flushed and logged?
Any outlet used less than about once a week should be flushed weekly, and every flush should be logged at the time it is done. Run each outlet until the temperature stabilises, hot reaching at least 50°C and cold dropping below 20°C, rather than for a guessed number of minutes, and record the temperature you actually reached. Higher-risk premises may flush more often; the frequency for each outlet belongs in the written scheme of control.
How long should I keep legionella flushing records?
Keep flushing records for at least five years, the retention period ACOP L8 sets for legionella control records. Paper sheets and electronic logs are both acceptable, provided the record can be produced promptly if an inspector, insurer or coroner asks for it. In practice, many duty holders keep a paper sheet in the plant room for the current period and file completed sheets, or export an electronic log, into an archive they can search by date.
Can I keep my flushing log on paper?
Yes. ACOP L8 accepts paper and electronic records equally; what matters is that the record is made, kept and retrievable. Paper suits a plant room wall and is hard to falsify after the fact, but it can be lost or damaged, so file completed sheets rather than leaving them indefinitely. An electronic log such as our log book tool exports to CSV and prints, which makes archiving and producing the record on request easier.
Related water hygiene products and services from trusted UK providers will appear here.