Hot water cylinders and calorifiers store and heat the water your building uses. If they are not working properly, they can create conditions that help legionella bacteria multiply.
What they are
- Hot water cylinders are commonly found in smaller buildings.
- Calorifiers are larger storage and heat-exchange units, used in bigger buildings like hotels, nursing homes and offices.
What can go wrong
- Water stored too cool. Warm water in the base of a cylinder is an ideal breeding area for bacteria.
- Sediment and scale build up and can shelter bacteria.
- Poor circulation leaves some parts of the system cooler than others.
- Undersized or overworked units struggle to keep the whole system hot.
- Lack of maintenance means problems go unnoticed.
Typical checks
- Storage temperature. Hot water is normally stored at a high enough temperature to control bacteria. Your risk assessment and the HPSC guidance set the figures to aim for. See our guide on water temperatures for legionella control.
- Return temperature. In circulating systems, the water returning to the cylinder should also stay hot.
- Draining and inspection. Typical practice is to drain, inspect and clean calorifiers periodically and check for sediment. The frequency depends on the system.
- Drain valves. Make sure they are accessible and work.
- Insulation. Check pipes and cylinders are insulated so heat is not lost.
- Record everything. Temperatures, inspections and repairs belong in your logbook.
Who should do it?
Day-to-day checks can be done by trained staff, with specialist help for servicing and repairs. Your legionella risk assessment will set out who is responsible and how often.
Your duties
The Safety, Health and Welfare at Work Act 2005 expects employers to manage risks to health. The HPSC national guidelines give detail on controlling legionella in hot and cold water systems.
Get in touch
A legionella risk assessment from Safer Solutions will review your hot water plant along with the rest of your system. Call 086 275 9728 or email info@safersolutions.ie for a friendly conversation. Learn about common legionella risks in buildings.