You need a log sheet that an auditor will accept, not a blank notebook page. The download below gives you both a printable PDF and an editable spreadsheet, laid out so each sentinel and TMV reading lands in the right column with nothing left to guess. Print it, clip it to a board, walk the round.
The sheet is the easy part. Filling it in so the entries actually mean something is where most records fall down.
What the template gives you
Two files, same columns. A PDF to print and carry on a clipboard, and an editable spreadsheet (works in Excel, Google Sheets or LibreOffice) if you would rather type as you go or keep a running file per building.
Each row is one outlet on one date. The columns, left to right:
- Date and operative initials — who took the reading and when.
- Outlet reference — a fixed ID, not “upstairs sink”. WC1-HWB, KIT-SINK, PLANT-CALO-FLOW. Match it to your asset register.
- Outlet type — sentinel hot, sentinel cold, TMV blend, calorifier flow/return, or low-use.
- Hot temperature (C) and time to reach it — the reading and how many seconds the tap ran.
- Cold temperature (C) and time to reach it.
- In range? — a simple yes/no against your target figures.
- Action taken / comments — left blank only if everything passed.
Keep one sheet per building or per circuit, not one giant sheet for a whole estate. It makes the missing rows obvious.
The field checklist: how to take each reading
Work the same route every month so nothing gets skipped. The order matters less than doing it identically each time.
- Start at the calorifier. Record the flow and return temperature. Stored hot water is commonly held at around 60C [2]. Note the actual figure, not “OK”.
- Run the furthest hot sentinel. Let it run and record the temperature once it stabilises, plus the seconds it took. As a general expectation, hot water should reach roughly 50C within about a minute at a sentinel outlet [1][2].
- Read the furthest cold sentinel. Cold water is commonly expected below 20C, reached within around two minutes of running [2]. Log the figure and the time.
- Take TMV-served outlets at the blend. A thermostatic mixing valve deliberately delivers warm, safe-to-touch water, so you are not chasing 50C there — you record the blended temperature and confirm the valve is behaving [2].
- Check low-use and seasonal outlets. The ones nobody runs are the ones that drift. Record them even when the reading is boring.
- Write the action in the moment. If a reading fails, note what you did — reflushed, raised a job, isolated the outlet — before you move on.
Verb-first, one line per outlet, signed at the bottom. That is the whole job.
A worked example
Three rows from a filled-in sheet, so the columns make sense:
| Date | Outlet ref | Type | Hot C / time | Cold C / time | In range? | Action |
|---|---|---|---|---|---|---|
| 04/06 | KIT-SINK | Sentinel hot | 52 / 50s | — | Y | — |
| 04/06 | WC3-CWS | Sentinel cold | — | 18 / 90s | Y | — |
| 04/06 | WC1-TMV | TMV blend | 41 / — | — | N? | Blend high; flagged for valve service |
Notice the third row. The figure itself is fine for a blend, but the operative still flagged it because it sat at the top of the expected window and the valve was due a check. A log sheet earns its keep when it captures that judgement, not just the digit.
The columns people leave blank
The same fields get skipped every time, and they are the ones an auditor reads first.
Time to temperature. A hot tap that eventually hits 50C after three minutes is not in control — it has a long dead leg or a recirculation fault. Without the seconds column, that reading looks identical to a healthy one. Record the time, always.
The action column on a pass. Counter-intuitively, leaving it blank is correct on a clean pass — but only if every operative does the same. Decide your convention and stick to it, so a blank means “passed” and never “forgot”.
Operative initials. An unsigned reading is an anonymous reading. If the round is challenged after an incident, you want to know who held the thermometer.
Outlet references that match the asset register. “Tap by the door” cannot be cross-checked against last month. Fixed IDs let you spot the outlet that quietly stopped being recorded.
For more on which points to read and why one in-range figure proves so little, see Temperature checks: the cornerstone of Legionella monitoring, and for the wider control-programme context, Monitoring water temperatures in a Legionella control programme.
Fill it in by hand, or auto-log in L8log
The paper sheet is genuinely fine for a single small building. It costs nothing, needs no signal, and survives a dropped clipboard.
It also has known failure modes: rows get skipped and nobody notices until the year-end review, handwriting is argued over, exceptions sit on a page instead of becoming a job, and “missing” looks the same as “in range but unwritten”.
A digital logbook closes those gaps. In L8log, the same temperature round becomes a structured task: the app prompts the outlets due this month, flags an out-of-range reading the moment you enter it, won’t let a sentinel quietly disappear from the schedule, and timestamps who recorded what. An auditor sees a complete, date-stamped trail instead of a folder you have to reassemble. Bluetooth probes can push the figure straight in, removing the transcription error entirely.
The pragmatic call: print the PDF today so this month’s round is covered, then read Setting up a digital Legionella logbook when you are ready to stop chasing paper.
A note on the figures
The temperatures, run-times and monthly frequency in the template are common expectations drawn from HSE guidance, not fixed legal numbers for your site [1][2]. Your written scheme of control, built from a competent risk assessment, sets the exact target figures, which outlets count as sentinels, and how often each is read. Treat the sheet as a structure to populate with your own assessed values — it is general guidance, not a substitute for that site-specific assessment or for advice from a competent person.
FAQ
How many outlets should be on my log sheet?
That comes from your risk assessment, not from the template. As a general expectation, monthly monitoring covers the sentinel outlets — typically the nearest and furthest from each hot and cold source — plus a rotating sample of others [1]. The sheet simply gives you a row for each.
Do I record a temperature for every TMV-served tap?
You monitor the TMV outlets your scheme identifies, recording the blended temperature at the fitting rather than chasing a hot figure, and the valves themselves are commonly checked and serviced on a separate annual cycle [2]. Keep TMV rows clearly typed so they aren’t read as failed hot sentinels.
How long should I keep completed log sheets?
Retain them long enough to show a continuous control history — your risk assessment and scheme of control set the period, and a rolling minimum of around five years is a common benchmark for water-hygiene records. Whether on paper or in software, the test is that you can produce an unbroken trail on request.
Sources
[1] HSE, “Legionnaires’ disease: Technical guidance (HSG274)”. https://www.hse.gov.uk/pubns/books/hsg274.htm [2] HSE, “Hot and cold water systems”. https://www.hse.gov.uk/legionnaires/hot-and-cold.htm