GENERAL SAFETY INFORMATION
EFFECTIVENESS IN COMBATING
LEGIONELLA
Water systems in buildings have been associated with
outbreaks of Legionnaires’ Disease, particularly in health
care facilities where occupants are significantly more
susceptible to infection.
In recognition of the risks in hospitals, a Code of Practice
for the Control of Legionella in Health Care premises has
been issued by the Department of Health (1991). Codes of
Practice applicable to other premises have been published
by other organisations, principally the Health and Safety
Executive (HS)(G70) and the Chartered Institute of Building
Services Engineers (CIBSE, TM13).
All Codes of Practice draw attention to the design and
operation of water systems with reference to avoidance of
factors that favour colonisation by Legionella bacteria.
These factors include stagnation, lukewarm conditions
(20°C to 45°C) and the accumulation of debris, scale and
corrosion in the base of tanks and calorifiers.
Andrews Water Heaters have commissioned an
independent evaluation of their products to investigate
their resistance to build-up of Legionella bacteria.
Experiments were conducted to determine whether,
following a substantial challenge by legionella
pneumophilia. After overnight and stagnation, the system
was rendered free from viable recoverable legionella. It
was found that at 61°C, following a challenge of
approximately 107 organisms per litre, within one hour,
more than 99.999% of organisms had been killed. After a
subsequent stagnation period, sampling did not reveal any
residual contamination. The design of the base of the
water heater precludes legionella colonisation, even after
build-up of debris. The burner positioning ensures that the
water at the bottom of the heater reaches the same, or
higher, temperatures as in the rest of the heater.
Based on data obtained through experiment, the Andrews
Water Heater can be described as legionella resistant as it
is considered unlikely that, at the temperature tested, the
organism would colonise the water heater and present a
possible health risk.
5
WARNING: If the information in this manual is not followed exactly, a fire or
explosion may result causing property damage, personal injury or death.
- Do not store or use gasoline or other flammable vapors and liquids in the
vicinity of this or any other appliance.
- WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any phone in your building.
• Immediately call your gas supplier from a neighbor’s phone. Follow the
gas supplier’s instructions.
• If you cannot reach your gas supplier, call the fire department.
- Installation and service must be performed by a qualified installer, service
agency or the gas supplier.
