25
INSTALLATION
9
Before connecting the thermal module the protection plugs
must be removed from the delivery, return and condensate
drain pipes.
9
Before connecting the thermal module, it is necessary to
clean the system. This step is absolutely required when the
appliance replaces another one on pre-existing systems.
In order to carry out this cleaning activity, if the old generator is
still installed on the system, it is advisable to:
− add a de-scaling additive.
− Operate the system with the generator on for around 7
days.
− Discharge dirty system water and flush the system one or
more times with clean water.
If the system is very dirty, repeat the last procedure one more
time.
If the old generator is not present or available, use a pump to
circulate the water + additive through the system for about 10
days and perform a final washing as described in the previous
paragraph.
Once the cleaning has been completed, it is recommended to
add a suitable protective fluid to the system's water before in-
stalling the thermal module.
In order to clean the heat exchanger's built-in water system,
please contact Technical Assistance Service
R
.
0
Do not use incompatible liquid detergents, including acids
(for instance, chloridric acid and similar) in any concentra-
tion.
0
Do not subject the heat exchanger to cyclical pressure
changes because fatigue stress is very dangerous for the in-
tegrity of system components.
2.7
Typical water system schematics
Block diagram 1: Circuit with thermal modules with their own circulator, connected in cascade.
EAF
EAF
PB
PI
P2
V2
S2
P
P3
V3
M
S3
UAC
SB
M
PR
SE
ZM
SS
PC
Depending
PC
Thermal module circulator
PB
Storage cylinder circulator
PR
DHW circulation pump
PI
System circulator (high temperature zone)
P2
Zone 2 circulator (low temperature)
P3
Zone 3 circulator (low temperature)
S2
Zone 2 sensor
S3
Zone 3 sensor
SB
Boiler sensor
SE
Outdoor sensor
SS
Primary sensor
V2
Mixer valve zone 2
V3
Mixer valve zone 3
ZM
Electronic device for zone management (accessory)
EAF
Domestic cold water inlet
UAC
Domestic hot water outlet
