Immergas ZEUS kW Export Guide

ZEUS kW
Export
Wall-hung, room sealed boilers
with storage tank
ZEUS kW Export

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ZEUS kW Export
Wall hung boiler with storage tank, sealed
chamber and fan assisted ue.
ZEUS 24 kW Export
ZEUS 28 kW Export
General specications.
ZEUS kW is wall-hung boiler with a sealed chamber and a
fan-assisted ue (type C) for central heating and domestic hot
water supply (DHW) with a storage tank.
anks to a special kit (option), the boiler can also be installed
in conguration B22.
It is equipped with a stainless steel storage tank and coil with
an overall 45-litre capacity.
e appliance is available with a useful heat output of 24 kW
(20,640 kcal/h) and 28 kW (24,080 kcal/h) with over 90%
useful eciency rating.
Both versions are equipped with electronic ignition, tempera-
ture and ame modulation control.
anks to new improved electronics, the appliance can be
connected to Comando Amico Remoto remote control, which
allows the boiler to be remotely controlled and managed with
the utmost simplicity.
e hydraulic circuit is equipped with a copper water-gas
exchanger and features a new hydraulic group made out of
composite material. is is where the pump and the electrical
3-way valve are housed (allowing the boiler water to circulate
around the central heating system or the coil in the storage
tank for the production of DHW), as well as the hydraulic
circuit control devices (3-bar safety valve, adjustable system
by-pass, etc.).
e intake of combustion air inside the sealed chamber and the
discharge of ue is assured by a fan controlled by a dierential
ue pressure switch.

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Main dimensions and connections.
Key:
G - Gas supply
R - CH return
M - CH ow
RC- DHW re-circulation (option)
AC- DHW ow
AF- Domestic cold water inlet
V - Power supply connection
Height
(mm)
Width
(mm)
Depth
(mm)
890 580 380
CONNECTIONS
GAS SYSTEM DHW
G R M AC AF
1/2” 3/4” 3/4” 1/2” 1/2”

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Key:
1 - Burner operating LED
2 - DHW function LED
3 - Central Heating function LED
4 - Temperature LED - Insucient circulation malfunction
5 - Temperature LED - Flow probe malfunction
6 - Temperature LED - No ignition malfunction
7 - Temperature LED - Overheating malfunction
Control panel.
8 - Temperature LED - Flue pressure switch malfunction
9 - DHW Stand-by / Remote control Selector - DHW and
Heating - Reset
10 - DHW temperature selector
11 - Heating temperature selector
12 - Boiler manometer

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ZEUS kW main components.
Key:
1 - Negative signal pressure point
2 - Positive signal pressure point
3 - Sample points (A air) - (F ue exhaust)
4 - Flue pressure switch
5 - Fan
6 - Primary heat exchanger
7 - Automatic vent valve
8 - Boiler pump
9 - Gas valve
10 - Motorized 3 - way valve
11 - Filling valve
12 - System expansion vessel
13 - DHW probe
14 - Stainless steel storage tank
15 - 3-bar safety valve
16 - draining valve
17 - 8-bar safety valve
18 - Storage tank draining valve
19 - Sealed chamber
20 - Flue hood
21 - Flow probe
22 - Combustion chamber
23 - Safety thermostat
24 - Burner
25 - Ignition and detection electrodes

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e hot water used for heating and DHW is produced by a pri-
mary and secondary (DHW) circuit according to demand.
ZEUS kW hydraulic diagram.
18 - Draining valve
19 - Motorized 3 - way valve
20 - DHW probe
21 - 3-bar safety valve
22 - Filling valve
23 - 8-bar safety valve
24 - Cold inlet one - way valve
25 - Storage tank drain valve
G - Gas supply
AC - DHW outlet
AF - Domestic cold water inlet
R - System return
M - System ow
Key:
1 - Gas valve
2 - Stainless steel storage tank coil
3 - Magnesium anode
4 - Stainless steel storage tank
5 - Automatic vent valve
6 - Burner
7 - Combustion chamber
8 - Primary heat exchanger
9 - Flue hood
10 - Fan
11 - Flue pressure switch
12 - Sealed chamber
13 - Flow probe
14 - Safety thermostat
15 - System expansion vessel
16 - Boiler pump
17 - Adjustable by - pass

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Primary circuit (boiler circuit).
e primary circuit (and its relative control and safety devices)
is enabled every time there is a heating or DHW request.
Operation.
e heat in combustion exhaust is transferred by copper ns
to the water-gas exchanger (8). e water-gas exchanger then
transfers such heat to the water circulating inside it thanks to
the boiler pump (16).
e water is then pushed directly into the system or it can be
diverted to the storage tank coil (2).
is depends on the position of the electric 3-way valve (19)
which, according to the type of request, either allows water to
ow through the central heating ow system (M) and return
(R) pipes or diverts the water towards the coil (2).
Flow rate - head graph.
e shape of the curve representing the ow rate-head ratio
will depend on how the system by-pass is adjusted; thus, the
position of the by-pass will provide more or less head to the
system. e graph below illustrates the characteristic curves
according to the by-pass adjustment.
Boiler pump (1).
e boiler pump operates on the primary circuit return, im-
mediately downstream of the 3-way valve which is connected
to. It is part of the integrated multi-function group made out
of composite material.
e automatic vent valve (2) is also housed in the hydraulic
group casing.
Primary heat exchanger (1).
e primary heat exchanger is a lamellar water-gas heat ex-
changer with copper pipes and ns (No. 77 ns on the 24 kW
boiler exchanger model and 89 ns on the 28 kW version). e
NTC central heating ow probe (2) and the safety thermostat
(3) are positioned on its outlet pipe (ow).
Primary heat exchanger is assembled with four tubes connected
in series (4).
Pipes with threaded ttings connect it to the pump ow and
the primary circuit ow.
Return
A = Head available to the system at third pump speed (screw is tight-
ened 1.5 turns from loose position)
B = Head available to the system at second pump speed (screw is tight-
ened 1.5 turns from loose position)
Head (kPa)
Flow rate in Liter/h
A
Head (m H2O)
ZEUS 24 kW
Head (kPa)
Flow rate in Liter/h
Head (m H2O)
ZEUS 28 kW
B
A
B
1
3
4
2
Flow
1
2

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Motorised 3-way valve.
e electric 3-way valve operates on the primary circuit return
and, according to the type of request (DHW or central heat-
ing), it either directs hot water to central heating system or
storage tank coil.
Such operation depends on the position of the shutter (5),
which either closes the way toward the system opening the way
toward the storage tank (DHW position) or vice-versa (central
heating position).
e shutter (5) can be shifted to either position by powering
the motor (1).
e hydraulic part consists in a group made of composite
material (2) (which includes the pump), driven by a motor (1)
which shifts the valve as necessary.
Operation.
When central heating or DHW position is required, the motor
(1) is switched on by the P.C.B.
Every 180° turn of the motor, shifts the shutter (5) and either
compresses (central heating position) or releases (DHW position)
the shutter opposing spring (4).
Both the spring (4) and the shutter (5) are located inside the
3-way cartridge (3).
When the requested position is reached, it alternatively opens
and closes one of the two limit micro-switches (6) inside the
motor casing (1).
Such procedure makes it possible for disconnection of power
supply to the motor, locking the motor in the position it is in
and enable motor function only when a dierent request is
received (DHW or central heating request).
Storage
tank coil
return
Pump
ow
System
return
PUMP
RETURN
SYSTEM
RETURN
COIL
RETURN

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Safety and control devices.
Adjustable system by-pass (2).
e adjustable system by-pass guarantees water circulation in
the primary circuit (between ow and return) even when high
resistance in the system would not allow circulation.
By-pass is assembled on the ow manifold group (1) and can be
adjusted by acting on a screw to be accessed from underneath
the valve support plate.
System lling valve group (3).
e system lling valve group consists in a ball valve located
between the boiler circuit and the cold domestic water inlet,
which allows the central heating system to be pressurized.
e cock is connected to a lling tting (4) which is connected
to the 3-way valve group.
Automatic vent valve (6).
e vent valve automatically expels any gaseous substances
from the boiler circuit.
e valve is located on the pump ow pipe directly on the
hydraulic group.
3-bar safety valve (5).
e safety valve ensures 3-bar safety pressure not to be ex-
ceeded.
It is inserted on the front of the ow manifold group (1) and
it is secured by a clip.
When triggered, the safety valve releases water from the ow
pipe.
System expansion vessel (7).
e expansion vessel compensates the variations in volume
caused when water is heated, and therefore it changes in
pressure.
e vessel has a 10-litre capacity (7.7 liter useful capacity) and
a 1.0 bar factory set pressure.
It is located above the storage tank and is connected to the
3-way valve group by a copper pipe.
System ow
1
2
5
46
3
7

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Secondary circuit (DHW circuit).
DHW circuit is activated every time it is necessary to adjust
the temperature of water in the storage tank (2) to desired
temperature measured by the DHW NTC probe (9).
Such procedure is due to DHW being drawn from a tap or to
compensate for heat loss in the water heater itself.
Operation.
Following a request for DHW, the integrated P.C.B. activates
the boiler pump (7) and enables the electric 3-way valve mo-
tor (8).
e valve then shifts to DHW position (see electric 3-way
valve operation paragraph), the system return pipe (R) closes
and at the same time the way toward the storage tank coil
opens up (4).
e above arrangement prevents circulation within the central
heating circuit and allows for circulation within the coil (4).
e coil surface allow for absorbing of heat in the primary
circuit by the domestic cold water.
erefore, during this phase, central heating function is halted
and DHW production is given priority.

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Storage tank.
e 45-litre storage tank with coil is made entirely out of stain-
less steel and is completely insulated with self-extinguishing
polystyrene.
e storage tank consists in an external cylinder the lower part
sealed by a ange (15) whose seal is guaranteed by a gasket
(16), which can be removed so the inside of the storage tank
(coil, anode, etc.) can be inspected through such opening
(“crawl space”).
A stainless steel pipe (4) is located inside the tank, shaped like
a concentric spiral (coil) which develops through the lower
part of the boiler. e heat exchange between the hot water
in the primary circuit and the water in the storage tank takes
place through the coil surface.
is keeps the water in the storage tank at a constant tem-
perature and guarantees instantaneous production of DHW
whenever water is drawn.
Storage tank integrity and function are guaranteed by the
following devices:
Anode (1).
e anode is inserted in the storage tank and protects it against
corrosive actions of galvanic currents.
It is screwed onto the external cylinder at the bottom of the
storage tank.
Polyphosphate dispenser (optional).
e polyphosphate dispenser prevents the formation of scale
on the coil surface. e kit is assembled on domestic cold
water inlet pipe.
Recirculation kit (option).
Recirculation kit allows for DHW recirculation system pipes
to be connected.
It consists in a pipe, which is inserted in the boiler after the
anode and relative plug have been removed.
When the kit is installed, the anode is screwed onto the end
of the pipe.
An additional kit is available (option) which includes a pump
for DHW recirculation system.
e kit is not protruding outside the boiler clearance while the
pump slightly extends beyond the plastic grille at the bottom
of the appliance.
DHW NTC probe (B2) (9).
e DHW probe allows integrated P.C.B. to read temperature
of water inside the storage tank.
It is secured to the external wall of the water tank and it is
inserted in an sample point.
Safety valve group (13).
e safety valve group is located in the lower part of the storage
tank near the domestic cold water inlet.
As well as an 8-bar valve (10) which prevents the storage tank
safety pressure from being exceeded, it includes:
- a lter, 10 l/min (24 kW) and 12 l/min (28 kW) ow limiter,
a storage tank draining valve with hose union (12) and a
one-way valve (see hydraulic circuit paragraph, detail “5”) in
order to ensure that increased pressure DHW does return
toward water mains supply.
DHW expansion vessel (11) (option).
DHW expansion vessel compensates for any variations in
volume caused by water in the storage tank.
It is connected to the safety valve group and has a 2-litre capac-
ity with a 3.5-bar factory set pressure.
11
21
9
1
19
10
12
15
16
2113
4
2
Cold water
inlet
Coil
ow
Coil
return
Domestic hot
water outlet

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e gas circuit consists in an atmospheric burner and a modu-
lating gas valve, which respectively allow gas combustion and
adjustment of gas ow.
Operation.
When electricity is supplied to the main coils (3) both shutters
inside the valve open, allowing gas to ow toward the burner.
e outlet ow rate/pressure is adjusted by acting on the gas
valve stabilizer through the modulation coil (1).
Fuel is injected through the burner nozzles (7) into the hori-
zontal Venturi pipes (ramps). A mixture of air and gas forms
inside the pipes and is then ignited by the spark generated by
ignition electrodes (5).
Modulating gas valve.
Gas valve (SIT 845) is equipped with two main coils (3) and a
modulating coil (1) managed by the integrated P.C.B.
It acts on the gas valve stabilizer and proportionally adjusts the
outlet pressure to the continuous current running through it
(see Gas adjustments).
Main electric coils (3).
ere are two ON-OFF type coils powered (230 V AC) by the
integrated P.C.B. when burner ignition is required.
e coils are connected in parallel and supplied by mains power
supply via a connector (2).
Modulation coil (1).
e modulation coil is a low voltage coil managed by the
integrated P.C.B.
It acts on the gas valve stabilizer and proportionally adjusts
the outlet pressure to the continuous current running through
it.
Gas circuit.
Burner.
e burner consists in horizontal Venturi pipes (6) into which
the gas is injected through the same number of nozzles (7)
assembled on the manifold (8).
e diameter of the nozzles varies according to the type of gas
used (see technical data sheet). ere are 11 nozzles on ZEUS
24 kW and 13 nozzles on ZEUS 28 kW.
Ignition takes place thanks to an integrated electronic P.C.B.,
which controls the ignition (5), and detection (4) electrodes.
Ignition electrode (5).
e ignition electrodes are controlled by the integrated P.C.B.,
which triggers an electric spark between the electrodes, and
the air-gas mixture ignites as soon as it comes into contact
with the spark.
e electrodes are located at the front of the burner.
Detection electrode (4).
e detection electrode is controlled by the integrated P.C.B.
and it detects whether the burner has been ignited.
It is located at the front of the burner near the ignition elec-
trodes.
1
3
2
4
5
6
7
8

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Gas adjustments.
In order to adjust maximum and minimum gas pressure it is
necessary to act on the valve. Any adjustments must comply
with the values indicated in the charts regarding each boiler
for the type of used gas (see the technical data sheets).
Use a dierential gauge to carry out any measurements. Con-
nect the positive pressure point to the gas valve outlet (4)
and to the positive pressure point on the ange with sample
points located on the upper part of the sealed chamber (see
the gure).
SIT 845 gas valve.
Maximum pressure adjustment.
Set the DHW temperature selector to maximum output and
then open a tap.
Turn the brass nut (3) clockwise to increase the burner pressure
and anti-clockwise to decrease.
Minimum pressure adjustment.
(First, adjust maximum pressure and then minimum pres-
sure). Disconnect power supply from the modulation coil; then
turn the screw (2) clockwise to increase the burner pressure
and anti-clockwise to decrease it.
Changing the type of gas.
Use Immergas kits in order to adapt the boilers to a type of
gas (natural gas or LPG) other than the gas the boiler was
manufactured for.
In order to change gas type, replace the burner nozzles and
move the “NATURAL GAS - LPG” (S8) gas type selector on
the integrated P.C.B. en adjust maximum and minimum
pressures on gas valve as described above.
Adjustment of maximum and minimum heat output in central
heating boiler operation can be set means of parameters (see
integrated P.C.B. operation).
Burner ignition pressure does not need to be adjusted be-
cause the P.C.B. does not require such calibration (see integrated
P.C.B. operation paragraph).
Key:
1 - Coil
2 - Minimum heat output adjustment screw
3 - Maximum heat output adjustment screw
4 - Gas valve outlet pressure point
5 - Gas valve inlet pressure point
6 - Protective cap
SIT 845 valve

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Flue circuit.
Operation.
After going through the water-gas exchanger (2), the combus-
tion products are conveyed into a hood (4) topped by a ue
extractor (5) (fan).
ZEUS 24 kW model only: above the water-gas exchanger (2) a
ue distribution plate is installed (12).
e fan ensured forced discharge of any ue gas and at the
same time creates a depression in the sealed chamber (3) which
allows combustion air intake from the outside.
Correct ue exhaust ow is ensured by a pressure switch (6)
which enables (or does not) burner ignition.
Air/ue sample points (7-8).
ere are two sample points on the upper side of the sealed
chamber (they are accessible from the front), which can be used
to take samples of combustion air (7) and ue (8).
e two sample points are closed by one single plastic plug.
Flue pressure switch signal pressure points (9-
10).
On the upper side of the sealed chamber there are two pressure
points (sealed by two screwed caps), which can be used to verify
the signal on either end of the ue pressure switch (6).
e negative pressure point (9) is connected to a Y-shaped
pipe (11) which is connected to the negative pressure point
of the ue pressure switch (6) and to the pressure point on
the fan.
e positive pressure point (10) is connected directly to the
inside of the sealed chamber.
2
4
5
9
10
8
11
7
6
12

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Flue pressure switch (6).
e ue pressure switch is located in the upper inside part of
the sealed chamber and due to its pressure points, it detects the
dierence in pressure between inside the fan (negative signal)
and the inside the sealed chamber (positive signal).
e signal measured by the pressure switch varies according
to the length of the intake/exhaust system and can be veried
at the pressure points on the upper part of the sealed chamber
(9-10).
When the ue pressure switch is triggered, it closes its contacts
(S6) which act on the integrated P.C.B., enabling (or not ena-
bling) burner ignition.
Intervention pressures
Flue pressure switch
ON
Head
(mm H2O)
OFF
Head
(mm H2O)
ZEUS kW 44 (4.5) 36 (3.7)
Fan (5).
e ue discharging fan operates downstream from the com-
bustion chamber and is physically installed on the upper part
of the ue hood (4) from where it extracts ue and directs
them to the ue system ducts the boiler is connected to. At
the same time, it ensures combustion air ow into the sealed
chamber.
e fan is controlled by the integrated P.C.B. and its function
essentially follows the burner operation.
Air/ue system.
(See instructions for air and ue terminals).
ZEUS kW is designed to be connected to push-t air/ue
ducts. It can be installed in the sealed chamber and fan as-
sisted ue conguration (type C) or by means of a special
kit, in the open chamber and fan assisted ue conguration
(type B22 ).
Open chamber and fan assisted ue congura-
tion (type B22 ) for outdoor installation in a
partially protected area. (see the gure).
Using a specic kit, it is possible to install the ZEUS kW boiler
in outdoor partially protected areas.
When arranged in such manner the appliance operates in
open chamber and fan assisted ue conguration (type B22
), thus allowing combustion air to be drawn directly from the
environment.
e accessories (bends, extensions, terminals) feature push-t
connections and the seal is guaranteed by lipped gaskets.
Intake.
In order to assemble the cover (1), remove the plug (3) closing
the intake hole on the upper part of the sealed chamber.
Intake of combustion air is drawn directly from the environ-
ment via the opening between the lower part of the lid (1) and
the upper part of the boiler.
Exhaust.
In order to connect 80 mm diameter ue ducts, t the ue
exhaust pipes in the ange (2); the tightness is guaranteed by
lipped gaskets.
By using the relevant accessories, the ue exhaust system can
be horizontal (A) or vertical (B).
In order to avoid problems with condensate, ue duct must
be limited to 5 meters (in a straight line) with normal pipes
and 12 meters (in a straight line) with insulated pipes.
e maximum length allowed is 12 straight meters.
To ensure boiler correct operation with such kit in B22 congu-
ration, it is necessary to adjust the ue shutter on reference
point “5” (see boiler instruction manual).
Open chamber and fan assisted ue congura-
tion (type B22 ) for indoor installation (see
below gure).
e above mentioned cover kit is to be installed. By removing
the side plugs on the sealed chamber, air is drawn directly from
the environment where the boiler is installed.
Flue is discharged through the 80 mm diameter ducts into a
single chimney or directly outdoor.
BA
3
1
2

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Air/ue kit.
e kits with the relative accessories allow for implementation
with four concentric systems and two twin pipe systems.
As far as head loss for each accessory is concerned, the al-
lowable combinations and the positioning of the ue shutter
(depending on the length of the ducts and the type of duct
used), comply with air and ue terminal instructions (see boiler
instruction manual).
e accessories (bends, extensions, terminals) feature push-t
connections and the tightness is guaranteed by lipped gas-
kets.
Ø 60/100 push-t horizontal concentric kit.
e ue duct (Ø 60 mm) is inserted directly in the intake
duct (Ø 100 mm).
Connect to the boiler using a 90° bend (2) which can be turned
and face any direction. Use the required extensions in order to
reach air and ue terminal (3).
Maximum allowable overall length without considering the
rst bend (2) is 3 straight horizontal meters.
Ø 80/125 push-t horizontal concentric kit.
e ue duct (Ø 80 mm) is inserted in the intake duct (Ø
125 mm).
Connect to the boiler using a 90° bend with a 60/100 diameter
(2) which can be turned in order to face any direction. Using
the 60/100-80/125 adapter (3) and the appropriate extensions,
connect to the air and ue terminal (4).
Maximum allowed overall length without considering the rst
bend (2) is 7.3 straight horizontal meters.
Sealed chamber and fan assisted conguration
(type C).
Exhaust.
Connection to the ue ducts takes place thanks to a ange (1)
or a anged bend to be xed to the tting (4) on the upper part
of the sealed chamber along with a special shaped gasket (2).
e ange shape changes depending on whether a twin pipe
or concentric system is used.
In the rst instance, the passage for the intake of combustion
air (5) is closed whereas in the second case, it is used.
e exhaust tting (4) features a ue shutter (6) which needs
to be adjusted to ensure correct boiler operation.
e appropriate adjustment depends on the type of duct used
and their length (see boiler instruction manual).
In order to adjust it, unscrew the front locking screw and move
the indicator to the correct position aligning its value with the
horizontal reference.
Intake.
Using the twin pipe system, connection to the intake ducts
is the same as for the ue ducts by connecting to the 80 mm
diameter hole (3) on the upper part of the sealed chamber.
If coaxial pipes are used, air intake takes place by exploiting
the concentric circle outside the ue tting (5).
1
25
4
3
1
26
4
35
5
4
1
2
3
6

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Ø 80/80 push-t twin pipe ue kit.
Both pipes have an 80 mm diameter.
Boiler connections are obtained by means of two anges,
discharging ue (4) through the central tting and taking air
in (3) from one of the two side holes.
e maximum allowed length (air + ue) is 33 straight hori-
zontal meters and 41 straight vertical meters.
In order to avoid condensate problems, ue duct length is to
be limited to 5 meters.
Ø 80/80 push-t insulated twin pipe ue kit.
e functional diameter is 80 mm for both pipes.
Boiler connections are obtained by means of two anges,
discharging ue (4) through the central tting and taking air
in (3) from one of the two side holes.
Tightness is ensured by special gaskets (6); they create an air
space with the external Ø 125 mm concentric pipe.
Maximum allowed length is 33 straight meters (air + ue).
In order to avoid problems with condensate, ue duct length
is to be limited to 12 meters.
Ø 80/125 push-t vertical concentric kit.
e ue duct (Ø 80 mm) is inserted in the intake duct (Ø
125 mm).
Connect to the boiler using a ange (2). Using the 60/100-
80/125 adapter (3) and the appropriate extensions, connect to
the 80/125 air and ue terminal with an aluminum tile (6).
Maximum allowed length is 12.2 straight vertical meters.
Ø 60/100 push-t vertical terminal kit.
e ue duct (Ø 60 mm) is inserted directly in the intake
duct (Ø 100 mm).
Connect to the boiler using a ange (2). Using the appropri-
ate extensions, connect to the 60/100 air and ue terminal
with an aluminum tile. e maximum length allowed is 4.7
straight vertical meters.
6
2
1
3
4
5
7
8
6
5
1
3
2
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5
9
7
4
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B
5
4
1
3
2
5678
810 11 9
A
B

STZkW ed 10/07 ZEUS kW Export
17
Technical Documentation Technical Documentation
Electric circuit.
e electrical circuit on ZEUS kW is a total slave to the inte-
grated electronic microprocessor P.C.B. which controls all
boiler function.
Control and safety devices run partly on 230 V AC power
supply voltage and partly on low voltage.
Key:
A5 - CAR interface board.
B1 - Flow probe
B2 - DHW probe
B4 - External probe (option)
CAR- Comando Amico Remoto remote
control (option)
CRD - Digital Comando Amico Remoto
remote control (option)
CZ - Zone control unit (option)
E1 - Ignition electrodes
E2 - Detection electrode
E4 - Safety thermostat
F1 - Neutral fuse
F2 - Line fuse
M1 - Pump
M20- Fan
M30- Motorized 3 - way valve
R5 - DHW temperature trimmer
R6 - Central heating temperature trimmer
R10 - Main switch
S6 - Pressure switch
S8 - Gas type selector
S20 - Room thermostat (option)
T2 - Ignition transformer
X40 - Room thermostat jumper
Y1 - Gas valve
Y2 - Gas valve modulation coil
230 V AC circuit.
Safety and control devices.
Detects whether the burner is it (enveloped by ame).
Connected to the integrated P.C.B.
Detection electrode
(E2)
Disconnects power supply to the circuit when the input current
exceeds 3.15 A.
Assembled on the integrated P.C.B.
Line fuse (F1)
Neutral fuse (F2)
Fuse
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STZkW ed 10/07 ZEUS kW Export
18
Technical DocumentationTechnical Documentation
Loads.
P.C.B. is always powered regardless of the position on the main switch (R10) (see integrated
P.C.B. operation).
Integrated P.C.B.
Powered by the integrated P.C.B. when there is a DHW, central heating or antifreeze
request.
Allows circulation in the primary circuit.
Pump
(M1)
Powered with main power supply voltage by the integrated P.C.B. when the burner needs
to be ignited.
Allows the ow of gas to the burner.
(Y1) gas valve
(main coils)
Ignition electrodes are controlled by the integrated P.C.B., which triggers electric spark
between the ends of the electrodes; the air-gas mixture ignites as soon as it comes into
contact with the spark.
Ignition electrodes
(E1)
Guarantees the ow of air to the sealed chamber and the ow of combustion products
to the ue terminal.
Powered by the integrated P.C.B.
Fan
(M20)
Allows ow water within in the primary circuit to be diverted from the central heating
system to the storage tank coil and vice versa.
Powered by the integrated P.C.B.
3-way valve
(M30)
Low voltage circuit.
Allows remote control of boiler operation (SUMMER/WINTER
switch, temperature adjustment and display, alarm display, reset, etc.)
and acts as a weekly timer-thermostat.
When CAR is installed, the pre-existing X40 jumper is to be
eliminated.
Comando Amico Remoto
remote control
(CAR) (optional)
See Comando
Amico Remoto
remote control
operation (CAR)
Safety and control devices.
Allows remote control of the boiler (SUMMER/WINTER switch,
temperature adjustment and display, alarm display, reset, etc.) and acts
as a weekly timer-thermostat.
When CRD is installed, the pre-existing X40 jumper is to be
eliminated.
Digital remote control
(CRD) (optional)
See Digital
remote control
operation (CRD)
It allows the boiler to function with 3 zone valves or external pumps
controlled by the relevant room thermostats.
Zone 1 is controlled (timed operation periods and temperatures) by
the CAR (when installed).
If the boiler is controlled by the CRD, the zone control unit
cannot be installed.
Zones control unit (CZ)
(external optional)
See zones control
unit operation