Legionnaires' Standard Legionella Thermometer Kit

Incorrect water temperature is a key risk factor for Legionella growth. The Legionella bacteria multiply in water at temperatures between 20 to 45 °C, particularly if a supply of nutrients is present, such as scale, rust, sludge or algae.

A typical method of control is to store cold water below 20 °C. Hot water should be stored above 60 °C and distributed at above 50 °C. Regular testing using a water temperature thermometer helps control legionella risks.

Current legislation means that you must organise a risk assessment if you are an employer or person in control of premises. The revised Approved Code of Practice (ACOP) issued by the Government's Health and Safety Executive (HSE) significantly extends the scope of its guidance on controlling legionella bacteria in water.

The code now applies to all workplace hot and cold water systems regardless of their capacity; the lower limit of 300 litres previously used to exclude domestic systems no longer applies. Whilst domestic systems may represent a risk, the code only applies to risk arising from work activity.

This means all employers managing premises with hot/cold water systems or wet cooling systems are legally responsible for identifying contamination risks and preventing or controlling them.

The Approved Code of Practice (ACoP L8) applies to all workplace hot and cold water systems, regardless of their capacity. Any employer, landlord, or facility manager overseeing premises with hot or cold water systems is legally responsible for identifying contamination risks and implementing a reliable temperature monitoring programme to control them.

To stop Legionella bacteria from spreading, you must keep cold water below 20 °C. Hot water needs to be stored at 60 °C or higher. When it comes out of the tap, hot water should be at least 50 °C (or 55 °C in healthcare buildings). The bacteria grow very fast in still water between 20 °C and 45 °C, which is why checking your temperatures regularly is so important.

This kit gives you everything you need to check your water systems accurately. Inside the handy zip pouch, you will find a Therma 1 digital thermometer. It comes with two probes: a waterproof surface probe for checking pipes and tanks, and a strong PTFE wire probe for hard-to-reach spots. You also get a free traceable calibration certificate in the box.

The Health and Safety Executive (HSE) says you must check your water often to follow the rules. Usually, you should test your hot and cold taps once a month. Hot water needs to reach 50 °C within one minute of turning on the tap. Cold water must drop below 20 °C within two minutes. Places with vulnerable people, like hospitals or care homes, must do daily checks on their main water outlets.