Short answer. Care homes are high-risk legionella sites because of complex water systems, infrequently used outlets and vulnerable residents, and control sits under COSHH 2002, the L8 Approved Code of Practice and HSG274 Part 2 guidance for healthcare premises. In England, the CQC also checks water safety as part of its inspection framework; the equivalent regulators apply in Wales, Scotland and Northern Ireland.
Why care homes are high risk
Several factors combine to make care homes one of the higher-risk settings for legionella.
Complex water systems
Care homes typically have extensive hot and cold water networks serving many outlets across multiple floors and wings. Long pipe runs, multiple risers and distant outlets mean water can sit in the 20 to 45°C growth range before it reaches the tap.
Infrequently used outlets
Temporarily unoccupied rooms, seasonal facilities and overflow bedrooms all create stagnation risk. Where occupancy fluctuates, keeping a consistent flushing regime running on every outlet is a genuine operational challenge.
Vulnerable residents
Older residents, people with chronic respiratory conditions, immunocompromised residents and those with reduced mobility are all at higher risk of contracting Legionnaires' disease and of developing severe complications if they do.
Assisted bathing and showering
Many residents need assisted bathing, which means more prolonged exposure to water aerosol from showers and baths than an independent user would have.
Temperature management
Care homes face a genuine tension between legionella control and scald prevention. HSG274 Part 2 sets a higher distribution temperature for healthcare premises, hot water stored at 60°C and reaching 55°C at outlets within a minute, rather than the 50°C general commercial figure, because of the additional infection risk to vulnerable occupants. Water at that temperature is also a scald risk, so thermostatic mixing valves (TMVs) are fitted at point of use, and they need proper installation, commissioning and regular maintenance to stay safe in both directions.
The legal framework
The underlying duty comes from COSHH 2002, which treats legionella bacteria as a biological agent to be controlled. L8, the Approved Code of Practice, and its supporting technical guidance HSG274 (in three parts) set out how to meet that duty in practice; L8 and HSG274 are guidance on how to comply with COSHH, not legislation in their own right. The Health and Safety at Work Act 1974 provides the general duty of care underneath all of it.
The duty holder, typically the care home provider or registered manager, needs a legionella risk assessment carried out by a competent person, a written scheme of control, routine monitoring that is actually carried out and recorded, and a review of the assessment whenever there is reason to believe it may no longer be valid, for example after a change to the water system, occupancy or use, rather than on a fixed statutory interval.
Essential control measures
Temperature control. Hot water stored at 60°C, reaching 55°C at outlets within one minute in healthcare and care settings, with TMVs fitted at point of use. Cold water should be below 20°C, ideally within two minutes of running. HSG274 Part 2 specifies monthly checks at sentinel outlets, with the remaining representative outlets checked on a rotational basis so that every outlet is covered over the course of a year.
TMV management. Every TMV should be identified, maintained on a schedule and checked to confirm it is operating within safe parameters. HSE scalding data puts a full-thickness burn at around 30 seconds' exposure at 55°C and around 5 seconds at 60°C, which is why a TMV that has drifted or failed is a genuine and fast-acting hazard for a resident with reduced mobility or sensation.
Flushing regime. Outlets that are not used regularly need a flushing programme: running the water, hot and cold, until the temperature has stabilised, which HSG274 treats as the practical measure rather than a fixed time. The written scheme should record what "stabilised" means for your system and set the frequency and duration accordingly, with dates, times and who carried it out logged.
Tank inspections. Cold water storage tanks should be inspected periodically, cleaned when necessary, and kept in good condition with properly fitted lids, insect screens and overflow arrangements.
Calorifier maintenance. Hot water calorifiers should be inspected and drained periodically to remove sediment, with temperatures checked at the base and top of the vessel.
Water sampling. Routine microbiological sampling can be appropriate where there is suspicion of legionella proliferation, or where features of the water system make temperature control alone difficult to rely on.
Regulatory oversight across the UK
In England, the Care Quality Commission checks water safety under regulations 12 (safe care and treatment) and 15 (premises and equipment) of the Health and Social Care Act 2008 (Regulated Activities) Regulations 2014, alongside its wider inspection framework. Inspectors expect to see a current risk assessment, evidence of ongoing monitoring and record-keeping, a documented written scheme of control, training records for staff responsible for water safety tasks, and evidence that findings are being actioned.
Care homes in Wales, Scotland and Northern Ireland are regulated by Care Inspectorate Wales, the Care Inspectorate, and the RQIA respectively, rather than the CQC; the underlying COSHH, L8 and HSG274 duties apply UK-wide regardless of which regulator inspects the home.
Bringing it together
A care home carries a higher legionella risk than most commercial buildings, and the consequences of getting it wrong are more serious given who lives there. A risk assessment by a competent person, a written scheme that reflects HSG274 Part 2's healthcare figures rather than general commercial ones, and consistent monitoring and record-keeping are what a regulator, and a resident's family, will actually look for.
HSE's guidance on legionella control, including L8 and HSG274, is available from HSE's Legionnaires' disease pages. A legionella risk assessment for care homes covers the water system, the written scheme and the monitoring records a CQC inspection or equivalent will ask to see.