Immergas HERCULES SOLAR 26 1A User manual

HERCULES
SOLAR 26 1A
Ecological floor-standing
condensing boiler
with stainless steel storage tank
integrate with solar circuit
HERCULES SOLAR 26 1 A

1
STHSC ed 0710 HERCULES Solar 26 1A
Technical Documentation Technical Documentation
HERCULES SOLAR 26 1A
Ecological oor-standing condensing
boiler with 200 litre storage tank
integrated with solar circuit
HERCULES Solar 26 1A
HERCULES Solar 26 1A combines the advantages of an
ecological condensing boiler with those of a oor standing
boiler with storage tank with heat output of 23.9 kW (20,554
kcal/h) and are equipped with a total premix combustion
system, which guarantees particularly low pollutant emissions
and allows functioning with methane or LPG. anks to
condensation technology, it is characterised for its high
eciency and for the large modulating eld (from 20÷100%
of the nominal heat output). e hydraulic circuit, made up
from one stainless steel water-gas coil exchanger, a hydraulic
manifold inserted as per standard and two pumps, means
that the boiler is suitable for the heating systems that require
high ow rate.
HERCULES Solar 26 1A can function in zone systems
controlled by pumps: it is, in fact, prepared to house the low
energy consumption pumps necessary to control up to 3 zones
on the heating system inside the casing. It is also prepared
for the realisation of mixed systems: one high temperature
zone (e.g. radiators) and two low temperature zones (e.g. oor
radiating panels) by inserting the optional kit inside the casing
(including pumps, mixer valves and zone management board).
e new zone management board allows to use the Remote
Control (optional) to control that considered to be the main
zone.
All hydraulic components of the solar circuit, solar
expansion vessel, solar safety valve, pump unit, thermostatic
mixing valve, etc... (except the solar collector) are integrated
General features inside the boiler casing. e P.C.B. also allows the control
of all solar heat circuit parameters, avoiding the use of a
dedicated control unit.
e new electronics allow the connection of the appliance
to the Comando Amico Remoto remote control and to the
Super Comando Amico Remoto remote control; both allow
to manage and control the boiler at a distance with great
ease. Using the Super CAR remote control it is possible to
indierently vary some settings from the boiler control panel
and from the Super CAR remote control panel, such as:
selection of Summer Winter, DHW set point, DHW comfort
status, Reset. e adjustment and the control of the appliance
are entrusted to a P.C.B. with continuous ame modulation.
e boiler functioning parameters are set using the buttons
and knobs while display of the status, functioning mode and
anomalies takes place on the back-lit digital display.
e DHW circuit is equipped with an 8 litre expansion vessel
and a 200 litre stainless steel storage tank which, as well as the
advantages of storage, guarantees the instantaneous production
of hot water. HERCULES Solar 26 1A must be installed using
the intake/exhaust kits or the ducting systems (Ø 60 mm rigid,
Ø 80 mm rigid and Ø 80 mm exible) realised in plastic and
designed expressly for Immergas condensing boilers.

2
STHSC ed 0710 HERCULES Solar 26 1A
Technical DocumentationTechnical Documentation
Main dimensions and connections
HERCULES Solar 26 1A
Key:
RA3 - Zone 3 high temperature system return G 3/4”
(optional)
MA3 - Zone 3 high temperature system ow G 3/4”
(optional)
RA2 - Zone 2 high temperature system return G 3/4”
(optional)
MA2 - Zone 2 high temperature system ow G 3/4”
(optional)
RB2 - Zone 2 low temperature system return G 1”
(optional)
MB2 - Zone 2 low temperature system ow G 1”
(optional)
RB1 - Zone 1 low temperature system return G 1”
(optional)
MB1 - Zone 1 low temperature system ow G 1”
(optional)
RA1 - Zone 1 high temperature system return G 3/4”
MA1 - Zone 1 high temperature system ow G 3/4”
G - Gas supply G 1/2”
AC - DHW output G 3/4”
AF - DHW inlet G 3/4”
RC - Recirculation G 1/2” (optional)
RP - G 3/4” solar panels return (optional)
MP - Flow from G 3/4” solar panels (optional)
SC - Condensate drain (minimum internal
diameter Ø 13 mm)

3
STHSC ed 0710 HERCULES Solar 26 1A
Technical Documentation Technical Documentation
HERCULES Solar 26 1A control panel
Key:
- Stand-by - On Button
A - Summer ( ) and winter ( ) functioning mode selection button
B - “COMFORT”( ) or “SAVING” DHW function button
C - (RESET)/menu exit (ESC) reset button
D - Menu entry button (MENU)/ data conrmation (OK)
1 - Domestic hot water temperature selector switch
2 - Domestic hot water temperature set
3 - Central heating water temperature selector switch
4 - Central heating temperature set
5 - Anomaly presence
6 - Display of boiler functioning status
8 - Flame presence symbol and relative power scale
9 and 7 - Primary heat exchanger output water temperature
10 - Boiler in Stand-by
11 - Boiler connected to remote control (Optional)
12 - Functioning in summer mode
13 - Anti-freeze function in progress.
14 - Functioning in winter mode
15 - DHW functioning in “COMFORT” mode
16 - Connection to external tools for technician
17 - Display of menu items
18 - Functioning with external temperature probe active
19 - Display of data conrmation or menu access
20 and 7 External temperature display
with external probe connected (optional)
21 - Display of reset or exit menu request
22 - Chimney sweep function in progress
23 - Boiler manometer
24 - Multifunction display

4
STHSC ed 0710 HERCULES Solar 26 1A
Technical DocumentationTechnical Documentation
HERCULES Solar 26 1A main components
Key:
1 - Stainless steel storage tank
2 - DHW recirculation pump (optional)
3 - 3-way valve (motorised)
4 - Zone 1 by-pass
5 - Zone 1 one-way valve
6 - Zone 1 pump
7 - Safety thermostat (Low temperature)
(optional)
8 - Flow probe (Low temperature)
(optional)
9 - Zone 2 pump (optional)
10 - Zone 2 one-way valve (optional)
11 - Zone 2 by-pass (optional)
12 - Mixing valve (optional)
13 - Solar expansion vessel
14 - Flue safety thermostat
15 - Burner
16 - Ignition electrode
17 - Detection electrode
18 - Venturi
19 - Gas nozzle
20 - Fan
21 - Manual air vent valve
22 - Domestic water inlet cock
23 - 8 bar safety valve
24 - Air intake pipe
25 - Safety valve with manometer
26 - 3 bar safety valve
27 - DHW mixing valve
28 - System lling valve
29 - Shut-o valve with thermometer
30 - Solar pump
31 - Flow meter
32 - Domestic hot water probe
33 - Condensate drain trap
34 - Polyphosphate dispenser (optional)
35 - Domestic hot water expansion vessel
36 - Solar system drain tting
37 - Storage tank emptying cock
38 - Sample points (air A) - (ue gases F)
39 - Positive signal pressure point
40 - Negative signal pressure point
41 - Manual air vent valve
42 - Air vent valve
43 - Zones management electrical
connection box (optional)
44 - Condensation module
45 - Hydraulic manifold
46 - System expansion vessel
47 - Flow probe
48 - Safety thermostat
49 - Collector draining valve
50 - System pressure switch (absolute)
51 - Boiler Pump
52 - Sealed chamber
53 - Gas valve
54 - System draining valve
55 - Magnesium anode
56 - Storage tank solar probe

5
STHSC ed 0710 HERCULES Solar 26 1A
Technical Documentation Technical Documentation
HERCULES Solar 26 1A wiring diagram
e hot water used for central heating and domestic hot water
is produced via a primary and a secondary circuit (DHW)
which are aected according to necessity.
Standard Conguration
Key:
1 - Storage tank emptying cock
2 - Magnesium anode
3 - Domestic hot water expansion vessel
4 - Domestic hot water probe
5 - Stainless steel coil for storage tank
6 - System draining valve
7 - Polyphosphate dispenser (optional)
8 - System lling valve
9 - 3 bar safety valve
10 - Collector draining valve
11 - Condensate drain trap
12 - Gas valve
13 - Gas valve outlet pressure point (P3)
14 - Air intake pipe
15 - Fan
16 - Gas nozzle
17 - Detection electrode
18 - Burner
19 - Flue safety thermostat
20 - Condensation module lids
21 - Condensation module
22 - Manual air vent valve
23 - Flue hood
24 - Air sample point
25 - Flue sample point
26 - Pressure point ΔP gas
27 - Flow probe
28 - Safety thermostat
29 - Ignition electrode
30 - Boiler Pump
31 - System pressure switch (absolute)
32 - 3-way valve (motorised)
33 - Venturi positive sign P1
34 - Venturi negative sign P2
35 - Air/gas Venturi manifold
36 - System expansion vessel
37 - Air vent valve
38 - Hydraulic manifold
39 - Zone 1 pump
40 - Zone 1 one-way valve
41 - Zone 1 by-pass
42 - Mixing valve lter
43 - DHW mixing valve
44 - Domestic water inlet cock
45 - Cold inlet lter
46 - Flow limiter
47 - Cold water inlet non-return valve
48 - 8 bar safety valve
49 - DHW recirculation pump
(optional)
50 - Solar stainless steel coil
51 - Solar expansion vessel
52 - Manual air vent valve
53 - Shut-o valve with thermometer
54 - Safety valve with manometer
55 - One-way valve (OV 20)
56 - Solar pump
57 - Flow meter
58 - One-way valve (OV 15)
RA1 - Zone 1 system return
(High temperature)
MA1- Zone 1 system ow
(High temperature)
G - Gas supply
AC - Domestic hot water outlet
AF - Domestic cold water inlet
RC - Domestic hot water re-circ.
RP - Return from solar panels
MP - Flow from solar panels
SC - Condensate drain

6
STHSC ed 0710 HERCULES Solar 26 1A
Technical DocumentationTechnical Documentation
Primary circuit (boiler circuit)
e primary circuit, with relative control and safety devices,
is started every time there is a central heating or domestic
hot water request.
Functioning (see hydraulic drawing)
e heat contained in the combustion products is absorbed
by the pipes of the water-gas primary heat exchanger with coil
inserted in the condensation module (17) which, then gives
the heat up to the water made to circulate inside the boiler
pump (26).
e water is introduced directly into the hydraulic manifold
(34) and therefore to the system or can be diverted inside the
storage tank coil (1).
is depends on the position of the motorised 3-way valve
(28), which depending on request, allows ow towards the
system ow and return pipes of the hydraulic manifold (34)
or causes diversion towards the coil (1).
Boiler pump (1)
Operates on the primary circuit return immediately after the
3-way valve to which it is connected. It is part of the integrated
multifunction unit realised in composite material.
ere is a seat on the body where the automatic air vent valve
(2) is housed.
1
2

7
STHSC ed 0710 HERCULES Solar 26 1A
Technical Documentation Technical Documentation
2
1
4
3
5
Primary heat exchanger
(condensation module)
It is formed from a casing that contains 4 elements with a
coil shape.
Each element is made up from 5 elliptical spirals (3).
e entire module is realised in stainless steel and its internal
part makes up the sealed combustion chamber and the
condensation chamber (2).
e rst three elements are aected directly by the action of
the cylindrical burner applied to the front, while the fourth
is arranged in the condensation chamber, which is separated
from the combustion chamber by sheet steel (see ue circuit).
To reduce head losses to a minimum and increase the ow rate
available to the system, the ow is made up from the parallel
connection of the rst two elements, the return, instead is
made up from the parallel connection of the last two elements.
e heat exchanger inlet is connected to the pump ow and the
outlet, on which the NTC central heating probe is positioned
(1), is connected to the primary circuit ow.
e primary circuit return and ow pipes are coupled using
threaded ttings with at gasket.
e ue hood (4) is connected to the rear using a relevant
gasket blocked by a metal ring and xed using three nuts to
the steel condensation module.
e condensate drain is also found in the lower part.
To ease the escape of any air bubbles still present in the coils,
there is a manual air vent in the upper part of the module (5).
FLUE GAS
RETURN
FLOW
EXHAUST
CONDENSATE

8
STHSC ed 0710 HERCULES Solar 26 1A
Technical DocumentationTechnical Documentation
Motorised 3-way valve
It is an electric 3-way valve operating on the primary circuit
return that allows, according to request (DHW or CH) , to
introduce boiler water into the CH system or the storage
tank coil.
is depends on the position of the shutter (5) which, closes the
passage towards the system opening it at the same time towards
the storage tank (DHW position) or vice versa (CH position).
e shutter (5) is moved into both positions by powering the
motor (1).
e hydraulic part is made up from a group of composite
material (2) that also integrates the pump and is put into
action thanks to a motor (1) that causes movement according
to necessity.
Operation.
When it is necessary to reach the CH or DHW position, the
motor (1) is activated by the P.C.B.
Functioning of the motor leads to the movement of the shutter
(5) and compresses (CH position) or leaves (DHW position) the
shutter contrast spring to release (4).
Both the spring (4) and the shutter (5) are situated inside the
3-way cartridge (3).
e hydraulic arrival at the requested position, alternatively
causes the opening and closure of one of the two end run micro
switches (6) set-up inside the motor box (1).
is allows to remove voltage to the motor blocking it in the
position reached and to enable motor functioning only in the
presence of a dierent request (DHW or CH signal).
RETURN
PUMP
RETURN
COIL
RETURN
MANIFOLD
RETURN
4
1
2
3
5
Flow
Pump
Return
coil
storage tank
Return
manifold
hydraulic

9
STHSC ed 0710 HERCULES Solar 26 1A
Technical Documentation Technical Documentation
Safety devices and controls
System lling (3).
It is a ball valve positioned between the boiler circuit and the
domestic cold water inlet that allows to pressurise the CH
system.
e valve is connected to the domestic cold water inlet unit (4).
System pressure switch (5).
Detects the pressure inside the primary circuit.
Its seat is on the ow pump body directly on the hydraulic unit
and is coupled to a micro switch that prevents functioning of
the burner when the pressure detected is below 0.3 bar.
Prevents overheating of the main heat exchanger.
Automatic air vent valve (6).
Allows the automatic expulsion of the gaseous substances that
may be present in the boiler circuit.
It is mounted on the pump ow directly on the hydraulic unit.
3 bar safety valve (7).
Prevents the safety pressure in the primary circuit from being
exceeded (3 bar).
It is situated in the right side of the boiler and is visible by
opening the right lateral door. It is positioned on the hydraulic
unit connection pipe - lling valve.
System expansion vessel (8).
It compensates the volume variation consequent to heating
the water, thus limiting the pressure variations.
It has a capacity of 12 litres (useful 4.2 litres) and a factory-set
pressure of 1.0 bar.
It is organised at the rear of the upper right zone of the
appliance.
8
4
3
7
65

10
STHSC ed 0710 HERCULES Solar 26 1A
Technical DocumentationTechnical Documentation
GIM Multifunction Integrated Unit
Before replacing the various components present on the GIM
unit, the water present inside the primary circuit must be
drained by opening the system draining valve positioned on
the storage tank return connection pipe.
Before draining, ensure that the system lling valve is closed.
ree-way valve cartridge replacement (1).
To replace the 3-way cartridge (1) slide the locking clip out (2)
and extract the small electric motor (3) and then unscrew the
screw fasteners (4) that x the cartridge (1) to the composite
body (6).
N.B.: when re-mounting the cartridge, pay particular attention
to correctly insert the two small sheet steel reinforcement
plates (5).
Pump motor replacement (7).
To replace the pump body, remove the 4 screws (8) that x the
motor (7) to the composite body (6).
Replacement of the automatic air vent valve (9).
To replace the air vent valve, the relative locking clip must be
removed and the valve extracted (9) paying attention not to
damage the relative O-ring.
N.B.: when re-mounting the air vent valve, pay particular
attention to insert the relative O-ring correctly.
System pressure switch replacement (10).
To replace the system pressure switch (10), slide the relevant
locking clips out.
N.B.: when re-mounting the system pressure switch, pay
particular attention to insert the relative O-ring correctly.
3
2
1
45
9
8
7
6
10

11
STHSC ed 0710 HERCULES Solar 26 1A
Technical Documentation Technical Documentation
Central heating circuit
HERCULES Solar 26 1A functioning with 1 pump (Zone 1)
(standard conguration)
Following a central heating type request, the P.C.B. starts the
boiler pump (2), powers the central heating pump (4) and
powers the electric 3-way valve motor (3) causing it to shift
to the central heating position.
In this way the passage towards the storage tank coil is closed
and that towards the hydraulic manifold is opened (1), into
which the water from the primary circuit is introduced.
e hot water is introduced directly into the system through
the ow (MA1) and return (RA1) pipes via the central heating
pump (4).
anks to functioning with the two pumps (2 and 4) and
the use of an open hydraulic manifold (1) the water ow rate
and the head available are particularly high (see ow rate/head
graphics).
FLOW
COILS
STORAGE TANK UNIT
RETURN
COILS
STORAGE TANK UNIT
RA1
MA1
1
4
2
3

12
STHSC ed 0710 HERCULES Solar 26 1A
Technical DocumentationTechnical Documentation
Central heating pump (4)
It operates on the system ow after the hydraulic manifold (1).
It is physically xed onto the system ow pipe and to the boiler
ow manifold, to which it is connected using threaded ttings.
Hydraulic manifold (1) (manifold).
It is an open manifold onto which the boiler and system ow
and return pipes are connected and which allows, along with
boiler (2) and CH pumps (4) (see previous page) to make a
ow rate and head available to the system that is high with
respect to the traditional boiler.
is takes place because the circulation inside the primary
circuit is guaranteed by the boiler pump and therefore the
CH pump head is not reduced by the appliance head losses.
e open manifold (1) also allows to mix the ow water with
a part of the return water and therefore supply a ow rate that
is higher than that circulating in the boiler.
To ease the escape of any air bubbles and gaseous substances,
there is an automatic air vent in the upper part of the hydraulic
manifold (2).
Safety devices and controls
By-pass (6).
Guarantees circulation in the primary circuit also when the
high resistance of the system does not allow it.
It is mounted between the system ow and return connection
pipes.
System lter (7).
It prevents any impurities present in the system from
obstructing the primary circuit (heat exchanger) and preserves
the one-way valves by preventing leaks occurring on the CH
system during DHW functioning.
It is inserted into the by-pass block in correspondence with
the tting to the system return pipe.
"Europa" system one-way valve (5).
Prevents undesired circulation in the system when the pump
(4) is not working.
It is inserted into the rst ow pipe of the respective by-pass.
N.B.: e pump, the system by-pass, the system lter and
the one-way valve of zone 1 are supplied as per standard,
while the others are included in the zone systems connection
kit (optional).
R
M
67
5
R1
M1
R2
M2
R3
M3
1
2
Primary
ow Primary
return

13
STHSC ed 0710 HERCULES Solar 26 1A
Technical Documentation Technical Documentation
Head available at zone 1 (standard) with by-pass inserted.
The use of the pump positioned downstream from the
hydraulic manifold allows to provide a high system ow rate.
e graphics below represent the trend of the head available
to zone 1 system (standard), depending on pump speed and
with the by-pass inserted between ow and return.
Head (kPa)
A
B
C
A - Head available to the system with the standard pump (1st zone) at maximum speed
B - Head available to the system with the standard pump (1st zone) at speed 4,5 (factory setting)
C - Head available to the system with the standard pump (1st zone) at speed 3
Head (m H2O)
Flow rate Litres/h

14
STHSC ed 0710 HERCULES Solar 26 1A
Technical DocumentationTechnical Documentation
HERCULES Solar 26 1A functioning with 2 or 3 additional homogeneous zones (optional)
(conguration with high temperature zones kit)
Any division of the zone system (2 or 3) requires the assembly
of a relevant kit inside the casing, which envisions the use of
the zones management board (21) (see "Digital zones board"
functioning) and additional pumps to be used (max 2) with
that mounted as standard.
With the installation of this kit, the pumps (7 and 10) are
connected to the hydraulic manifold (1) (return) and to the
respective system ow pipe (ow) into which the primary
circuit water is introduced directly.
e return pipes of zones 2 or 3 are tted to the same hydraulic
manifold (1) connected to the primary heat exchanger return.
e functioning of each pump (7 and 10) depends on the
functioning request of the respective room thermostats (or
CAR remote control for zone n.º 1) connected to the zones
control unit (21).
For every additional zone the lit includes a pump, a system by-
pass (9 and 12) and a one-way valve (8 and 11) to be inserted
into the system ow pipe.
N.B.: Regarding the wiring diagram, settings, signals, etc. see
the " Zones digital control unit" technical sheet.
FLOW
COILS
STORAGE TANK UNIT
RETURN
COILS
STORAGE TANK UNIT
21 11 8
7
10 12 9
RA1
MA1
RA2
MA2
RA3
MA3

15
STHSC ed 0710 HERCULES Solar 26 1A
Technical Documentation Technical Documentation
Head at the other additional high temperature zones.
e use of several pumps positioned downstream from the
hydraulic manifold allows to provide a high system ow rate.
e graphics below represent the trend of the head available to
system zones 2 and 3 at high temperature, depending on pump
speed and with the by-pass inserted between ow and return.
Head (m H2O)
Head (kPa)
Flow rate Litres/h
A
B
C
A - Head available to the additional zones (2nd and 3rd zone) at maximum speed
B - Head available to the additional zones (2nd and 3rd zone) at speed 4,5
C - Head available to the additional zones (2nd and 3rd zone) at speed 3

16
STHSC ed 0710 HERCULES Solar 26 1A
Technical DocumentationTechnical Documentation
HERCULES Solar 26 1A functioning with mixed systems with 1 additional mixed zone (optional)
(conguration with Low Temperature Kit)
The coupling to a mixed system divided into two zones
envisions the installation of the "low temperature kit" inside
the casing.
e assembly of this kit leads to the use of a three-way mixing
valve (7), a zone management board (21) (see "Zones digital
control unit" functioning) prepared for control of the valve and
the pump (10), a system by-pass (13) and one-way valve (9)
to be inserted into the system return pipe.
anks to this system, the boiler can serve two zones operating
at differentiated temperatures; a high temperature zone
(example radiators) and a low temperature zone (example oor
radiating panels).
“high temperature” zone (zone 1 already standard).
is portion of circuit is envisioned to operate at an ideal
temperature for radiator plants, fan coils etc.
It is served by the standard pump and its temperature is
adjusted by acting on the boiler control panel.
“low temperature” zone (zone 2).
is portion of circuit is envisioned to operate with oor
panel systems.
It is served by a pump (10) which, via a motorised 3-way
mixing valve (7), introduces water into the system at constant
temperature.
To allow this, the 3-way valve (7) is controlled by a P.C.B.
(21) that varies the position depending on the pre-selected
temperature (from 25°C to 50°C).
is setting is made on the boiler control panel.
e temperature of the ow water is obtained by mixing the
high temperature circuit ow water and the low temperature
FLOW
COILS
STORAGE TANK UNIT
RETURN
COILS
STORAGE TANK UNIT
circuit return water in variable quantities according to
necessity,(see hydraulic diagram).
e control of the correct mixing is entrusted to an NTC probe
(12) connected to the zones control unit (21).
21 913
7
10
RA1
MA1
RB1
MB1
12

17
STHSC ed 0710 HERCULES Solar 26 1A
Technical Documentation Technical Documentation
Head (m H2O)
Head (kPa)
Flow rate Litres/h
A
B
C
A - Head available to the additional zones (2nd zone) at maximum speed
B - Head available to the additional zones (2nd zone) at speed 4,5
C - Head available to the additional zones (2nd zone) at speed 3
N.B.:Regarding the wiring diagram, settings, signals, etc. see
the " Zones digital control unit" technical sheet.
Head available at the additional low temperature zone.
In functioning condition with mixed systems, the use of several
pumps guarantees a greater total ow rate to the system.
e graphics below represent the trend of the head available to
the low temperature zone system, depending on pump speed
and with the by-pass inserted between ow and return.

18
STHSC ed 0710 HERCULES Solar 26 1A
Technical DocumentationTechnical Documentation
HERCULES Solar 26 1A functioning with mixed systems with 2 additional mixed zones (option-
al)
(conguration with Low Temperature Kit)
e division of the mixed system into three zones requires the
assembly of a relevant kit inside the casing, which envisions the
use of the zones management board (21) (see "Digital zones
board" functioning) , two additional pumps to that already
mounted as per standard (10 and 17), two 3-way mixing valves
(7 and 14), two system by-passes (13 and 20) and two one-way
valves (9 and 16) to be inserted into the system return pipes.
anks to this system, the boiler can serve three zones operat-
ing at dierentiated temperatures; a high temperature zone
(example radiators) and two low temperature zones (example
oor radiating panels).
“high temperature” zone (zone 1 already standard).
is portion of circuit is envisioned to operate at an ideal
temperature for radiator plants, fan coils etc.
It is served by the standard pump and its temperature is
adjusted by acting on the boiler control panel.
“low temperature” zone (zone 2).
is portion of circuit is envisioned to operate with oor
panel systems.
It is served by a pump (10) which, via a motorised 3-way
mixing valve (7), introduces water into the system at constant
temperature.
To allow this, the 3-way valve (7) is controlled by a P.C.B.
(21) that varies the position depending on the pre-selected
temperature (from 25°C to 50°C).
is setting is made on the boiler control panel.
e temperature of the ow water is obtained by mixing the
high temperature circuit ow water and the low temperature
circuit return water in variable quantities according to
FLOW
COILS
STORAGE TANK UNIT
RETURN
COILS
STORAGE TANK UNIT
necessity,(see hydraulic diagram).
e control of the correct mixing is entrusted to an NTC probe
(12) connected to the zones control unit (21).
21 716
10
17 920 13
14
RA1
MA1
RB1
MB1
RB2
MB2
19
12