---
title: "Legionella temperature monitoring log sheet: free template and how to fill it in"
source_url: https://legionella.io/articles/legionella-temperature-monitoring-log-sheet-free-template-and-how-to-fill-it-in/
canonical_url: https://legionella.io/articles/legionella-temperature-monitoring-log-sheet-free-template-and-how-to-fill-it-in/
pillar: "Digital Logbooks & Record Keeping"
summary: "Grab a free Legionella temperature log sheet (PDF and editable spreadsheet) and learn how to record sentinel and TMV readings so entries stand up to an audit."
primary_keyword: "Legionella temperature monitoring log sheet"
date_published: 2026-01-19
date_reviewed: 2026-06-26
author: "Legionella.io editorial team (REMOTE TECH LTD)"
reviewed_against: "HSE L8 and HSG274 guidance"
region: "United Kingdom"
license: "(c) REMOTE TECH LTD. Quote freely with attribution and a link to source_url."
---

# Legionella temperature monitoring log sheet: free template and how to fill it in

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](https://legionella.io/articles/temperature-checks-the-cornerstone-of-legionella-monitoring/), and for the wider control-programme context, [Monitoring water temperatures in a Legionella control programme](https://legionella.io/articles/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](https://legionella.io/articles/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