Frost Protection And Legionella - andrews MAXXflo EVO Series Installation And Maintenance Manual

5.4 FROST PROTECTION & LEGIONELLA
5.4.1 FROST PROTECTION
The Heater is fi tted with automatic Frost Protection. Provided there is mains power, gas connected and the
heater is not in a lockout condition, if the temperature registered by the DHW tank temperature sensor falls
below 5°C the heat engine will ignite to bring DHW tank temperature up to 6°C before turning off again.
5.4.2 ANTI-LEGIONELLA GENERAL
Water systems in buildings have been associated with outbreaks of Legionnaires' Disease, particularly in
health care facilities where occupants are signifi cantly more susceptible to infection.
European policies and good practices, principally the European Agency for Safety and Health at Work (100 EN)
draw attention to the design and operation of water systems with reference to avoidance of factors that favour
colonisation by Legionella bacteria. Advice includes :
• Controlling the release of water sprays
• Avoid storing water at temperatures between 20ºC and 45ºC
• A minimum tank temperature of 55
• Avoid the accumulation of debris, scale and corrosion in the base of tanks and calorifi ers
• Avoid water stagnation
• Avoid using materials which harbour bacteria and other micro-organisms
This heater has been designed to minimise the formation of Legionella bacteria. The pumped tank charging
process ensures that the water at the bottom of the tank reaches the same temperature as in the rest of the
tank and all of the water is circulated, with no stagnation possible. A hatch in the main tank can be used for
inspection and cleaning. Only metals listed in 4MS are used in this heater, and the heater has a WRAS UK ap-
proval pending.
5.4.2 ANTI-LEGIONELLA SETTINGS
DHW Menu
Line no Description
1640 Legionella Function
1641 Legionella function periodi-
cally
1642 Legionella function weekday
1644 Legionella function time
1645 Legionella function setpoint
1646 Legionella function duration
1647 Legionella function circulation
pump
Commissioning
C must be maintained for at least 6 hours per day
o
Factory default Notes
Off Choose to have the legionella function activat-
ed on a fi xed weekday (parameter 1642), every
(parameter 1641) number of days or switch the
function off .
7 days No of days before the legionella function will
activate
Sunday Fixed day the legionella function will activate
01:00 Time the legionella function will start
70 C The setpoint to be achieved for the legionella
O
function
10 mins The length of time the DHW tank sensors and
B39 circulation return sensor (if fi tted) should
achieve the setpoint, before the function is
completed. If the legionella function cannot be
performed successfully within a 48 hour period,
an error message will be displayed.
On Choose whether the circulation pump Q4 is on
or off when the legionella function is active
45 MAXXfl o EVO