41
ECOTHERM
Heat transfer solutions
®
Operating Instructions High Capacity Water Heaters Models EHRE/EHPE & EDRE - ELC 11
9.4 The remote controlled anti-
legionella circuit
to avoid growth of legionella
bacteria in the hot water tank, the
anti legionella circuit can be shifted
externly via the swiching contact
input X16 from the boiler control or
in the parameter services. at closing
of the input X16 the whole boiler is
heated to 65° C.
Warning: The installation of
a cold water mixing valve is
recommended to avoid increased
danger of scalding during the
legionella cycle.
ChArGING state:
as in normal operation, except for
the following changes:
When the temperature at T2 (lower
part of storage tank) reaches
65ºC, the charging process will be
terminated and the system is set to
the COOLING state (if activated).
9.5 Defouling cycle
the patented heat exchanger defouling
cycle or eXsCale function inhibits the
formation of deposits such as lime scale
by quickly cooling the heat exchanger
using cold water taken from the storage
tank. the function is active while the
Economizer is in the STAND-BY state.
Display page s13, s14, s15 is used
to set the duration of each of the two
available eXsCale function variations.
the
SINGLE-RUN
variation
runs first, followed by the AUTO-
eXsCale variation.
●
SINGLE-RUN
Cold water is constantly cycled
through the heat exchanger
independant of temperature.
Display
page s13 is used to set the duration of
the run. to deactivate, enter single
run time 0. Auto-Exscale is initiated
upon completion of the single run.
9.7 Emergency operation
(Refer also to Section 12)
for
emergency operation the pumps
can be rewired to permanent
operation and the control valve
manually opened and closed. as
a further alternative for primitive
temperature control, the sensor t2
can be replaced with a thermostat
(eg type RAK 120020), which
operates the control valve, primary
and secondary pumps. set the
thermostat to max. 45ºC and limit
the boiler input temperature to 60°C.
9.8 Limiting boiler return
temperature (see 7.3.2.5.14)
some district heating companies
require a guaranteed maximum
return temperature in the primary
circuit. the optional sensor t5
should be ordered if this feature is
required. if the return temperature
is above the set value for a longer
time as set in the service menu,
then the return limit will become
active, i.e. the control unit regulates
charging via the return temperature
measured at sensor t5. additionally,
the charging process is only
switched off by the upper sensor
t1. if within the set time the return
temperature falls below the set
value, then the return limit remains
inactive and has no effect on
charging.
Legionella operating and renturn
flow limitation respectively peak
load operating condition and
sliding operating are not possible
at the same time.
tank Charging
●
AUTO-EXSCALE
Auto-Excale is initiated if the
temperature of one or both of
the sensors t3 or t4 are higher
than the value entered in display
page S11. Auto-Excale cycles cold
water periodically through the heat
exchanger until the temperature of
each sensor t3 and t4 fall below
the value entered in display page
s12. Display page s14, s15 is used
to set the duration of each Auto-
Excale period in seconds. Auto-
exscale is paused for 1 minute after
each period. enter duration 0 to
deactivate.
EXSCALE state:
Display:‘Mode NORMAL STAND-BY‘
‚eXsCale‘
the outputs are set to:
secondary pump = on
Primary pump = off
Burner demand = off
Control valve = CloseD
9.6 Delta-T operating mode
this mode is for use in warm
summer months when the variable
primary circuit delivery temperature
from the boiler should be used to
govern the temperature of the hot
water. The spreading T4 > T1 is
shown.
if the required hot water
temperature is e.g. 51ºC, then the
primary circuit delivery temperature
must be 55ºC. if the primary circuit
delivery temperature rises to 57ºC,
then the tank set value will also be
increased to 52ºC. this function
is limited to a maximum hot water
temperature of 60ºC.
