# Carry out a legionella risk assessment

Source: https://help.mucka.ai/gas-certs/carry-out-a-legionella-risk-assessment
Category: Certificates
Last updated: 2026-08-27

> The water system risk assessment landlords ask for alongside the gas check. Eleven sections, a risk rating rather than a pass or fail, and three printed pages.

A legionella risk assessment records the state of a property's water system: the outlets, the temperatures, the storage, and who might be exposed. Landlords commonly ask for one alongside the annual gas safety check, which is why it sits on the Gas tab in **New certificate** with the rest of your work.

## Be clear what it is

This is a **risk assessment**. It records what you found and rates the property. It is **not** a water sample result, and it does **not** certify a property free of legionella. The document says so on its face, and the app says so too, because neither of us can vouch for something nobody tested for.

If a customer is asking for water sampling or a certificate of compliance, that is a different job and a different provider.

## It is not a gas document

Two things follow, and both are deliberate:

- **No Gas Safe number is asked for, and none prints.** Legionella work is not a Gas Safe activity. You will not be blocked from approving because your card is out of date, and the assessment carries no Gas Safe logo.
- **There is no pass or fail.** Every other certificate here ends in Pass, Pass with defects or Fail. This one ends in a **property risk classification** — Low, Medium or High — because that is what a risk assessment concludes. A "PASS" beside a High rating would be nonsense.

## Filling it in

**Summary first.** Three boxes: what the system is and how you found it, anything you have already put right, and what still needs doing.

**Then the sections.** Each one has a location box and a list of things to answer:

- **Main kitchen / drinking water** — starts with whether it is mains fed or tank fed, then four checks.
- **Main bathroom** — seven checks.
- **Other outlets** — add as many as the property has. En-suites, utility rooms, outside taps. Give each one a location so they can be told apart on the printed assessment.
- **Calorifiers, water heaters and boilers**
- **Cold water storage tanks**
- **Exposure** — susceptible people, and whether anything generates a spray.

Every line takes **Yes**, **No** or **Not assessed**. "Not assessed" is a real answer, not a blank, and it prints as those words. If you did not look at the loft tank, say so — an assessment that quietly leaves out what it did not cover claims more than it did.

Answer a line and it asks whether action is required. Say yes and it asks you to rate the risk and lets you write it up and take a photo. That rating is the bit that has to be filled in: an action with no rating is an unfinished finding, and Mucka will hold the Approve button until you set it.

Only the **kitchen** and the **main bathroom** have to be finished before you can approve. The rest are yours to fill or leave — plenty of properties have no cold water storage tank at all, and you should not have to invent answers about one.

## What comes out

**Three portrait pages**, unlike every other certificate here, because this document really is that long:

1. Who it is for, the summary boxes, the kitchen and the main bathroom.
2. The other outlets, the calorifiers, the tanks and the exposure section.
3. The standing advice, your comments and both signatures.

The advice printed at the end is the same five lines on every assessment. You can see them in the form before you approve so there are no surprises about what is going out with your name on it.

## The review date

The paper assessment has no review date on it anywhere. Mucka suggests **twelve months**, so the property joins your renewal list and you get chased before it lapses, and you can change it to whatever you think is right. It is our suggestion, not a legal deadline, and it is worth saying that to the customer.