Why We Check Temperatures

Temperature is the main way we stop Legionella. If hot water is hot enough and cold water is cold enough, the bacteria cannot grow. We check temperatures to prove the water is safe.

What Temperatures Are Safe?

Hot Water

• Stored in cylinder: 60 degrees C or hotter
• Return pipe: 50 degrees C or hotter (55 in hospitals)
• At the tap: 50 degrees C or hotter within 1 minute (55 in hospitals)

Cold Water

• In the tank: 20 degrees C or colder
• At the tap: 20 degrees C or colder within 2 minutes

How Often to Check

• Sentinel taps (first and last on each loop): Every month
• Cylinder flow and return: Every month
• Cold water tank: Every month
• All other taps: Once a year

How to Check

1. Find the tap you need to check (use the site list)
2. Put a thermometer in the water stream
3. For hot water: wait 1 minute and read the temperature
4. For cold water: wait 2 minutes and read the temperature
5. Write down: date, time, tap name, temperature, and pass or fail
6. If it fails, tell someone so it can be fixed

What is a Sentinel Tap?

Sentinel taps are the first and last taps on each pipe loop. If the first and last taps are OK, the ones in between are probably OK too. Think of it like checking the front and back doors of a building - if they are secure, the middle is likely fine.