Immergas ZEUS Superior Series User manual

Technical documentation Technical documentation
STZS ed 06/03
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ZEUS SUPERIOR
ZEUS Superior
Manual service centrala termica
murala Immergas zeus superior cu
boiler
ZEUS 21 Superior
ZEUS 24 Superior
ZEUS 27 Superior
- GENERAL FEATURES
ZEUS Superior is a wall-hung room sealed fan-assisted boiler featuring a "Gaudium Magnum" device for
fully exploiting the characteristics of this 54 l boiler in AISI 316L stainless steel.
The appliance is regulated and controlled by means of a printed microprocessor control board which,
through a display, shows the state of boiler operation (temperature, safety devices, etc.) and enables it to
be connected (optional) to the Remote Friend Control, to the zones unit and to the Multisystem Water
Disconnector.(D.I.M.)
The range includes three electronic-ignition versions with heat outputs of 24.4 kW (21,000 kcal/h), 27.9
kW (24,000 kcal/h) and 31.4 kW (27,000 kcal/h).
The hydraulic circuit features a high-head copper water-gas exchanger, an electric 3-way valve, a 2 l
d.h.w. expansion vessel, an adjustable system by-pass and a device that permits to increase the
maximum available flow of the domestic hot water (Gaudium Magnum).
Combustion air flow into the sealed chamber and flue extraction are ensured by a fan, the correct
operation of which is controlled by a differential pressure switch.
- MAIN DIMENSIONS AND CONNECTIONS
DIMENSIONS (mm)
HEIGHT WIDTH DEPTH
ZEUS 21/24/27 900 600 450
ATTACCHI
GAS SYSTEM DOMESTIC
WATER
G R M U E
ZEUS 21/24/27 1/2 “ 3/4 “ 3/4 “ 1/2 “ 1/2 “
V - electric connection
G - gas supply
R - system return
M - system delivery
S - recirculation (optional )
U - domestic hot water outlet
E - domestic cold water inlet

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ZEUS SUPERIOR
ZEUS 21-24 Superior MAIN COMPONENTS
1 - Intake points (A=air) (F=flue)
2 - Flue safety pressure switch
3 - Adjustment and limit NTC probe
4 - Primary heat exchanger
5 - Combustion chamber
6 - Burner
7 - Pump
8 - Gas valve
9 - Motorized 3-way valve
10 - System filling valve
11- Sealed room
12- Automatic air vent
13- Flue hood
14- Expansion vessel
15- Ignition and detection electrodes
16- Domestic hot water NTC probe
17- Overheating safety thermostat
18- 316L stainless steel storage tank
19- 3 bar safety valve (system)
20- Pump pressure switch
21- 8 bar safety valve (domestic hot water)
22- Gaudium Magnum device
23- Storage tank drain valve
24- Fan
25- Positive signal pressure point
26- Negative signal pressure point
27- System drain valve
28- Adjustable system by-pass
29- Domestic hot water expansion vessel
30- Max d.h.w. flow limit thermostat

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ZEUS SUPERIOR
ZEUS 27 Superior MAIN COMPONENTS
1 - Intake points (A=air) (F=flue)
2 - Flue safety pressure switch
3 - Adjustment and limit NTC probe
4 - Primary heat exchanger
5 - Combustion chamber
6 - Burner
7 - Pump
8 - Gas valve
9 - Motorised 3-way valve
10- System filling valve
11- Sealed room
12- Automatic air vent
13- Flue hood
14- Expansion vessel
15- Ignition and detection electrodes
16- Domestic hot water. NTC probe
17- Overheating safety thermostat
18- 316L stainless steel storage tank
19- 3 bar safety valve (system)
20- Pump pressure switch
21- 8 bar safety valve (d.h.w.)
22- Gaudium Magnum device
23- Storage tank drain valve
24- Fan
25- Positive signal pressure point
26- Negative signal pressure pointr
27- System drain valve
28- Adjustable system by-pass
29- Domestic hot water expansion vessel
30- Max d.h.w flow limit thermostat

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ZEUS SUPERIOR
CONTROL PANEL
1 - Green heating operating indicator
2 - Heating temperature selector
3 - Domestic hot water temperature selector
4 - Green domestic hot water operation indicator
5 - 0/SUMMER and CAR/WINTER switch
6 - Gaudium Magnum operation switch
7 - Green Gaudium Magnum operating indicator
8 - Storage tank thermometer
9 - Boiler pressure gauge
10- Reset
11- Temperatures and diagnostics display
12- Yellow burner operation indicator

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ZEUS SUPERIOR
HYDRAULIC CIRCUIT
1 - Storage tank drain valve
2 - One way valve
3 - Coil
4 - Gas valve
5 - Magnesium anode
6 - Storage tank
7 - Pump
8 - Burner
9 - Combustion chamber
10- Primary heat exchanger
11- Flue hood
12- Fan
13- Flue safety pressure switch
14- Sealed room
15- Adjustment and limit NTC probe
16- Automatic air vent
17- Expansion vessel
18- Overheating safety thermostat
19- Pump pressure switch
20- Pump pressure meter
21- Domestic hot water. NTC probe
22- System drain valve.
23- Motorised 3-way valve
24- System filling valve
25- Adjustable system by-pass
26- 3 bar safety valve
27- D.h.w. expansion vessel
28- 8 bar d.h.w. safety valve
29- Gaudium Magnum device
30- Cold water inlet filter
31- Max flow limit thermostat
G – Gas supply
U – Domestic hot water outlet
E – Domestic cold water inlet
R – System return
M – System delivery
The hot water for the heating system and for the domestic circuit is produced by a primary circuit
and a secondary (domestic) circuit that are activated according to demand.
PRIMARY CIRCUIT (BOILER CIRCUIT)
The primary circuit with the relative control and safety devices is activated with each heating or
domestic circuit demand for water.
- OPERATION
The copper blades of the water-gas exchanger (10) absorb the heat contained in the flue gas
produced by combustion.
Those blades then transfer the heat to the water being circulated inside by the boiler pump (7).
The water is introduced directly into the plant or can be deviated inside the cylinder coil (3).
This depends on the position of the electric 3-way valve (23) which, depending on the demand,
allows water to flow through the plant delivery (M) and return (R) pipes or deviates it to the coil (3).

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ZEUS SUPERIOR
- CIRCULATOR
This operates on the primary circuit return and is
located on the brass header assembly of the electric
three ways valve.
It is connected to the monobloc and exchanger by
means of threaded connecting pipes.
The pumps used differ according to boiler output (see
head - flow graph).
The body is equipped with a threaded fitting which
on the21 and 24 versions is used for the connection of
the expansion vessel and of the automatic vent valve,
while on the 27 version is used for the directly
connection of the automatic air vent.
.
21 and 24 versions 27 version
- FLOW HEAD GRAPH
The curve that represents the relation between the
flow rate and the available head depends on system
bypass adjustment which, depending on its position,
gives the system greater or less head.
The graphs are refereed to the pump operating at top
speed with:
- A = Bypass disconnected (screw fully tightened)
- B = Standard bypass adjustment (screw tightened
by 4.5 turns with respect to fully-tightened position)
- C = Bypass open (screw fully loose)
ZEUS 21 Superior
ZEUS 24 Superior ZEUS 27 Superior
- PRIMARY HEAT EXCHANGER
This is a water-gas blade type exchanger with copper pipes
and fins at the outlet of which an NTC heating probe (5) is
located.
The size differs according to boiler heat output.
The four pipes passing through the exchanger are connected
in parallel (1) two by two, to reduce flow resistance to the
utmost and provide a greater available head.
It is connected to the pump flow and to the primary circuit
flow by means of coupling pipes (2) with O.R. seal (4).
These are secured by means of special forks (3).

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- SAFETY DEVICES AND CONTROLS
System by-pass (6)
This ensures water circulation in the primary circuit
(between flow and return) even when this is prevented
by the high resistance of the system.
It is mounted on the delivery manifold and can be
adjusted by means of a screw accessible from the
bottom part of the valve plate.
System filling valve (5)
This valve is installed between the boiler circuit and the
domestic circuit cold water inlet is used to pressurize the
heating system.
Downstream of the cock, an one way valve is fitted (nr 2
of hydraulic circuit) that prevents accidental flow of
water from the primary circuit to the water network
(d.h.w. circuit).
Its seat is located in the lower part of the monobloc where
it is screwed on.
Pump pressure meter (2)
This detects the difference in pressure at pump
extremities.
Its housing is in the delivery manifold and is coupled to
a micro-switch (3) that prevents burner operation in the
event of pump blockage or no water in the boiler circuit.
Prevents primary exchanger overheating.
3-bar safety valve (4)
Prevents safety pressure (3 bar) being exceeded in the
circuit.
On the versions 21 and 24 is fitted to the rear part of the
delivery manifold group, while on the version 27 is
fastened in its front part by means of a socket head screw.
When this trips, water exits from the flow pipe.
Automatic air vent (7)
Automatically expels any gaseous substances in the
boiler circuit.
On the versions 21 and 24 , the valve is screwed on the water
side of the expansion vessel.
On the version 27 is mounted on the pump body.
Expansion vessel (8)
Compensates changes in volume following heating of water
and permits reducing pressure changes.
It has a pre-load pressure of 0.8 bar and a capacity of 8 l
on the versions 21-24 and 10 l on the version 27.
It is located in front of the storage tank .
21 and 24 versions
27 version
21-24versions 27 version

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HYDRAULIC CIRCUIT
SECONDARY CIRCUIT (D.H.W. CIRCUIT)
The domestic hot water circuit is engaged every time the water contained in the storage tank and
measured by means of the d.h.w. NTC sensor (4) has to be restored to the desired temperature.
This occurs when domestic hot water is used and to restore the losses due to thermal dispersion.
- OPERATION
Following a d.h.w. request, the modulation board starts the boiler pump (7) and powers the
motor of the electric 3-way valve (8).
The consequent movement of the valve to domestic hot water position (see 3-way electric valve
operation), closes the system return pipe (R) and, at the same time, opens the return pipe of the
storage tank coil (4).
This way, circulation is allowed in the coil (4) which, through its walls, enables the cold
domestic water to absorb the heat contained in the primary circuit water.
In this phase, the central heating function is disconnected as the production of d.h.w. has
priority.

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- STORAGE TANK
This AISI 316L STAINLESS STEEL storage tank has a useful capacity of 60 l.
It consists of an external sleeve enclosed at the bottom by a flange fixed by 12 screws.
A STAINLESS STEEL cylindrical pipe with a concentric spiral shape (coil) is inserted inside and is coiled
along all the height of the storage tank.
Heat is exchanged between the hot water in the primary circuit and the water contained in the cylinder
through the walls of the coil.
This keeps the water in the cylinder at a constant temperature and guarantees instant availability of domestic
hot water on demand (21.000, 24.000 e 27.000 kcal/h according to the versions).
If necessary, the coil can be removed from the storage tank after taking off the lower inspection flange.
The following devices ensure that it operates correctly and is maintained in good condition:
Anode (1)
It is inserted in the storage tank and protects it against the
action of galvanic currents.
It is screwed onto the external sleeve at the bottom of the
storage tank.
Polyphosphate metering unit (optional)
This prevents any limestone deposits from accumulating on
the walls of the coil.
The special kit is mounted on the domestic cold water circuit
inlet.
Gaudium Magnum (6)
(see description and operation Gaudium Magnum)
Recirculation kit (optional)
This is used to connect the pipes of any recirculation system
of the domestic hot water circuit.
It consists of a pipe that is inserted into the tank after having
removed the anode with relative plug.
When the kit is installed, the anode must be screwed to the end
of the pipe.
Domestic hot water NTC sensor (NB) (9)
This allows the printed control board to detect the temperature
of the water contained in the storage tank.
It is attached to the external wall of the storage and inserted
inside an immersion trap.
Maximum flow d.h.w limit temperature thermostat (3)
It is a clicson thermostat which supplies the solenoid valve of
the Gaudium Magnum device.
It is fitted on the external wall of the storage tank.
Safety valve unit (13)
This unit is located in the lower part of the cylinder near the
domestic circuit cold water inlet.
In addition to an 8-bar valve (10) that prevents the safety
pressure from being exceeded inside the storage, it also
includes:
- a filter, a cylinder drain valve with hose fitting (12) and a
one-way valve (“5” domestic circuit) to prevent a pressure
increase following heating of the domestic circuit hot water
from causing water to return toward the water mains.
Domestic hot water circuit expansion vessel (11)
It compensates for volume variations following heating of the
water contained in the cylinder.
It is connected to the safety valve unit and has a capacity of 2 l
at a pre-load pressure of 3.5 bar.

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- GAUDIUM MAGNUM (6)
This device is fitted between the cold
water inlet (inlet) and the safety valve
group (outlet).
Inside it works an electrovalve that in
stand-by condition allows the water
passage through a flow limiter (1) (10
l/min for versions 21 and 27, 12 l/min for
version 24)
When the electrovalve (3) is supplied the
water flows trough a supplementary
passage through a 6 l/min flow limiter (2)
- Operation
The valve is electrically enabled (230 VAC) setting the switch “Gaudium Magnum”, located on
the control panel, on position .
It starts to work when the limit thermostat of max flow (3), fitted on the storage tank, detects a
temperature upper 50 °C.
When the temperature gets down under 41 °C, the limit thermostat of max flow (3)
automatically deactivates the valve (3).
When the storage tank temperature is high, this system permits to have an high domestic hot
water flow rate.
Instead when the temperature gets down, the hot water flow rate is limited in order to restore
rapidly the hot water temperature.
Re-setting Gaudium Magnum switch on “0” position, the valve (3) is always deactivates.
N.B.: in order to activate the “Gaudium Magnum” operation, the adjustment knob of domestic hot water
temperature must be adjusted from 6 to 9.
Service centrale Immergas NON STOP
www.imoca.ro
www.reparatii-centrale-termice-nonstop.ro

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ZEUS SUPERIOR
- MOTORIZED 3-WAY VALVE
This is a 3-way electric valve operating on the return pipe of the primary circuit that permits,
according to the type of request (domestic hot water or central heating), running boiler water into
the central heating system or into the storage tank coil
This depends on the position of the shutter (3) which impedes transit towards the system and at the
same time permits this towards the storage tank (d.h.w. position) or vice versa (central- heating
position).
Movement of the shutter (3) in both positions is achieved by energizing the motor (1).
Operation
To move to the heating or domestic
hot water circuit, the motor (1) is
activated by the control card.
Activating the motor, whose rpm is
reduced by a special gear system,
begins rotating a disc (6) with an
eccentric connection on the shaft of
that motor.
The moving disc activates a special
coupling (5) that, with each 180°
rotation, compresses (heating
position) or releases (domestic circuit
position) the plug valve contrast
spring (4).
Hydraulically reaching the requested position causes first one limit switch (2) to open and then
another to close.
This allows the voltage to be cut off to the motor, freezing it in the position reached and enabling
motor operation only when a different request (domestic circuit or heating signal) is received.

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ZEUS SUPERIOR
GAS CIRCUIT
The circuit consists of an atmospheric burner and a modulating type valve for gas combustion
and gas flow adjustment respectively.
- OPERATION
When the main coils (3) are energized, both inner valve shutters open, allowing the gas to flow
towards the burner.
The flow rate/outlet pressure is regulated by means of the gas valve stabilizer and the modulation
coil.
By means of the burner nozzles (7), the fuel is injected into the venturi pipes (ramps) inside which
the air-gas mix is obtained that is ignited by the spark from the ignition electrodes (5).
- MODULATING GAS VALVE
The gas valve (SIT 845) features two main coils and a third modulation coil controlled by the
adjustment board.
The maximum and minimum outlet pressure settings can be made on this valve (see gas
adjustments).
Main electric coils (3)
These two ON-OFF coils are fed (230 Vac) by the control
card to ignite the burner.
They are electrically connected in parallel and fed by
mains voltage through a special connector (2).
Modulation coil (1)
This low-voltage coil is controlled by the modulation card.
It controls the gas valve stabilizer and can be used to vary
the outlet pressure so that it is proportional to the d.c.
signal conveyed through it.
SIT 845
- BURNER
The burner consists of horizontal venturi pipes (6) in which the gas is injected by an equal number of
nozzles (7) mounted on the special header (8).
The number of nozzles is 13 in the 21,000 kcal/h version, 15 in the 24,000 kcal/h version and 16 in the
27,000 kcal/h version .
Ignition occurs by means of an electronic board (unit) which controls the ignition electrode (5) and
detection electrode (4).
Ignition electrodes (5)
They are controlled by the ignition unit that
generates an electric discharge between the two
electrodes.
They are mounted on the front of the burner between
the first and the second gas ramp (Venturi tube).
Detection electrode (4)
This is controlled by the ignition unit and detects
burner ignition.
It is positioned on the front of the burner on the
ramp alongside the ignition electrodes.

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ZEUS SUPERIOR
GAS ADJUSTMENTS
Max and minimum gas pressure adjustments can be made respecting the values shown on the
page’s 31 and 32.
- SIT 845 VALVE
After having connected the leads of
a differential pressure gauge to the
gas valve outlet (4) and to the
positive pressure connector at the
top of the sealed chamber (see
figure), do the following :
Maximum pressure setting
- Do a d.h.w. request (open a tap)
and setting the temperature selector
at maximum.
Turn nut “3” clockwise to increase
the pressure to the burner and
counter-clockwise to reduce it.
Minimum pressure setting
(to carry out after the maximum
pressure setting)
- After cutting off the power supply
to the modulation coil, turn screw
“2” clockwise to increase the
pressure to the burner and counter-
clockwise to reduce it.
1) Modulation coil 4) Gas valve outlet pressure connector
2) Min. power setting screw 5) Gas valve inlet pressure connector
3) Max. power setting screw 6) Protective cap
- CHANGING TYPE OF GAS
Adaptation to a type of gas different to that for which the boilers are intended, can be done by using the
special kits (natural gas or LPG).
The changeover consists in replacing the burner nozzles and in moving to the modulation board of the
“NATURAL GAS- LPG” (CM3) bridge.
The minimum and maximum pressures are then set on the gas valve in the way described above.
Adjustment of the minimum and maximum output during the heating phase and of burner ignition
pressure (see table below) can be done by means of the respective trimmers mounted on the modulation
board (see modulation board operation).
Soft ignition values in mbar (mm H2O)
Natural gas LPG
ZEUS 21/24 Superior 25 65
ZEUS 27 Superior 23 70

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ZEUS SUPERIOR
FLUE CIRCUIT
- OPERATION
The combustion residues, after investing the water-gas exchanger (1), are conveyed to a hood (3) at
the top of which is a draught diverter (4).
Operation of the fan ensures forced extraction of the flues and at the same time creates a vacuum in
the sealed chamber (2) that permits extraction of the combustion air from outside.
Correct flue extraction is controlled by a differential pressure switch (5), operation of which enables
or does not enable burner ignition.
- AIR/FLUE SAMPLING TRAPS (6-7)
The top outer part of the chamber features two
sumps with screw closing accessible from the
front and through which combustion air (6) and
flues (7) can be extracted.
- FLUE PRESSURE SWITCH
SIGNAL PRESSURE POINT (8-9)
The top outer part of the sealed chamber
features two pressure points with screw closing
for measuring the signal at the ends of the flue
pressure switch (5).
The negative pressure point (8) is linked
through a Y-pipe to the top of the draught
diverter and to the negative pressure point of
the flue pressure switch.
The positive pressure point (9) is directly linked
to the inside of the sealed chamber.

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ZEUS SUPERIOR
- FLUE PRESSURE SWITCH (5)
This is positioned in the top inner part of the sealed chamber and, by means of the points provided, reads
the difference in pressure between the top of the draught diverter (the point where the extractor is
positioned and operates) and the inside of the sealed chamber.
The signal measured from the pressure switch varies according to the length of the extraction/exhaust
terminals and is measured by the special pressure points fitted to the top part of the sealed chamber (8-9).
Its operation causes a deviation of a switch contact that acts on the unit (IGN. UNIT) and enables or fails
to enable burner ignition.
- FAN (4)
The extractor operates downstream of the combustion chamber and is physically "rested" on the top part
of the hood (3) from which it extracts fumes into the exhaust pipes to which the boiler is linked.
It is controlled from the ignition unit and its operation coincides with that of the boiler.
The fans used differ according to the output of the appliance (21,000, 24,000 and 27,000 kcal/h).

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ZEUS SUPERIOR
EXTRACTION AND EXHAUST SYSTEMS
(see extraction and exhaust end instructions )
ZEUS Superior is prearranged for connection to the special coupling type extraction and exhaust pipes.
- EXHAUST
Connection to the exhaust pipes is done by means of a
flange (1) or a flanged curve to be fastened to the union
(4) on the top part of the sealed chamber after placing in
between a special shaped seal (6).
The flange differs according to whether the doubled or
concentric system is used. In the first case, the opening
for extraction of combustion air (5) is closed, while in the
latter case, this is used.
For correct boiler operation, a diaphragm (7) must be
fitted on the exhaust (4) in between the flange used (1).
Diaphragms of different diameter are available which
must be fitted according to the type of pipe and its length
(see boiler instruction booklet).
- EXTRACTION
Using the doubled system, connection to the extraction
pipes is done in the same way as the exhaust pipes, by
connecting up to the 80 mm diameter hole on the top part
of the sealed chamber.
The hole is normally closed by means of a special cap (2)
equipping the boilers.
If coaxial pipes are used, extraction is done through the concentric hole outside the exhaust pipe (5).
- EXTRACTION EXHAUST KIT
The kits and relevant accessories make it possible to use four concentric systems and two doubled systems.
As regards pressure drop relating to each accessory, the various possible combinations and the use of the
diaphragms to be fitted according to the length of the pipes, see the instructions concerning the extraction and
exhaust ends (boiler instruction booklet). The accessories (curves, extensions and end pieces) are of the coupling
type and seal is provided by special lip seals.
Coupling type horizontal concentric kit 60 /100
The exhaust pipe (φ60 mm) is fitted inside the extraction
pipe (φ100 mm).
Connection to the boiler is made using a 90° curve (1)
that can be positioned in any direction and which, by
means of the necessary extensions, must be connected to
the special extraction and exhaust end (2).
Max possible overall length beyond the first curve (1) is
3 straight and horizontal metres.
Coupling type horizontal concentric kit 80 /125
The exhaust pipe (φ80 mm) is fitted inside the extraction
pipe (φ125 mm).
Connection to the boiler is made using a 90° curve
diameter 60/100 (1) that can be positioned in any
direction and which, by means of the adapter 60/100-
80/125 (2) and necessary extensions, must be connected
to the special extraction and exhaust end (3).
Max possible overall length beyond the first curve (1) is
7.3 straight and horizontal metres.

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Coupling type vertical concentric kit 60 /100
The exhaust pipe (φ60 mm) is fitted inside the
extraction pipe (φ100 mm).
Connection to the boiler is made using a flange (1)
that, by means of the necessary extensions, must be
connected to the special 60/100 extraction and exhaust
end with aluminium tile.
Max possible overall length is 4.7 straight and
vertical metres.
Coupling type vertical concentric kit 80 /125
The exhaust pipe (φ80 mm) is fitted inside the
extraction pipe (φ125 mm).
Connection to the boiler is made using a flange (1)
that, by means of the adapter 60/100-80/125 (3) and
necessary extensions, must be connected to the special
80/125 extraction and exhaust end with aluminium tile
(2).
Max possible overall length is 12.2 straight and
vertical metres.
80/80 coupling type separator kit
Both pipes have a diameter of 80 mm.
Connections to the boiler are made using two special
flanges for exhaust (1) from the centre pipe and
extraction (2) from the side hole.
Max possible length (extraction + exhaust) is 33
straight horizontal metres and 41 straight
vertical metres.
To prevent condensation problems, the exhaust pipe
should not be more than 5 m long
Insulated 80/80 coupling type separator kit
Both pipes have a working diameter of 80 mm.
Connections to the boiler are made using two special
flanges for exhaust (1) from the centre pipe and
extraction (2) from the side hole.
Insulation is obtained thanks to special seals (3)
whereby an air space can be created by means of a φ
125 mm external concentric pipe.
Max possible length (extraction + exhaust) is 33
straight metres.
To prevent condensation problems, the exhaust pipe
should not be more than 12 m long

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ZEUS SUPERIOR
ELECTRICAL CIRCUIT
CAR Remote control
CZ Control xone unitt
DL1 Central heating operation LED
DL2 D.h.w. operation LED
DL3 Flame LED
E1/E2 Ignition electrodes
E3 Detection electrode
EP Gaudium Magnum solenoid valve
F Fuse
IG Main switch
IP Gaudium Magnum switch
LP Gaudium Magnum operating
indicator
MOD Modulation coil
MP Circulator
MV Fan
NB D.h.w. NTC sensor
NE External sensor (optional)
NR Central heating NTC sensor
P1 Room thermostat jumper
PU1 Reset button
SP Pump pressure switch
SV Flue pressure switch
TA Room thermostat
TP Max flow limit thermostat
TS Overheat. safety
thermostat
VD Electric three-way valve
V/G Gas valve
The electric circuit is interlocked with a microprocessor electronic board that controls boiler functions.
The control and safety devices work in part at mains voltage and in part at low voltage.
230 V AC CIRCUIT
SAFETY DEVICES AND CONTROLS
Detection electrode (E3) This detects ignition of the burner by whose flame it is invested.
It is connected to the detection circuit of the ignition unit.
Fuse This interrupts power to the circuit when amp draw is over 3.15 A.
It is fitted on the modulation board.
Fuse
3.15 A 250 V
“Gaudium
Magnum” switch
(IP)
Enables the operation of the Gaudium Magnum solenoid valve (EP),
which is supplied by the maximum flow limit thermostat (TP).
0 - solenoid valve closed (not supplied)
- solenoid valve enabled (supplied by the closing of the
maximum flow limit thermsostat switch) (TP)
2-contacts switch

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Depending on position, this allows:
Main switch
(IG)
0 - circuit not powered
- d.h.w. and CAR function (optional)
-d.h.w. and central heating function.
3-position switch
Max flow limit thermostat
(TP)
It is screw up on the external wall of the storage tank.
With the Gaudium Magnum switch (IP) in position, powers the
solenoid valve of the Gaudium Magnum device (EP) when measures a
temperature higher than 50 ºC.
Interrupts electrical supply when the temperature falls below 41 ºC.
Clicson double-
contact thermostat
Overheat. safety device
(TS)
When the safety temperature (100 ºC) is exceeded, this interrupts power
to the main coils of the gas valve.
It is positioned on the flow pipe at the primary exchanger outlet.
Clicson double-
contact
thermostat
LOADS
3-way electric valve
(VD)
Deviates the flow of water of the primary circuit from the heating circuit to the boiler coil
and vice versa.
It is powered by the modulation board.
Circulator
(MP)
Permits circulation of water in the primary circuit.
This is powered by the modulation board whenever there is a demand for d.h.w.,
heating or antifreeze.
Fan (MV)
Ensures the flow of air inside the sealed combustion chamber and the exit of flues produced
by combustion.
Powered by the modulation board.
Gas valve (V/G)
(main coils)
This is powered by the ignition control unit when the burner has to be ignited.
Permits flow of gas to the burner.
“Gaudium Magnum”
electro valve
(EP)
Permits to increase the maximum available flow of domestic hot water (see Gaudium
Magnum operation).
Powered when the “Gaudium Magnum (IP) is in position and by the maximum flow
limit thermostat (TP)
“Gaudium Magnum” (LP)
operating indicator
Displays on the control panel the operation of the “Gaudium Magnum” function..
Is a green lamp connected in parallel to the “Gaudium Magnum” solenoid valve(EP).
Ignition control unit
(IGN. UNIT)
Controlled by the modulation board when the burner has to be ignited.
Controls the devices needed for ignition (gas valve, ignition electrodes) and flame detection
(ionisation electrode).
Ignition electrodes
(E1 - E2)
These provoke an electric spark that ignites the air/gas mix.
They are controlled by the control unit ignition transformer (IGN. BOARD)
Modulation board This is powered when the main switch (IG) is positioned in (summer or CAR) or
(winter) (see modulation board operation).

Technical documentation Technical documentation
STZS ed. 06/03 20 ZEUS SUPERIOR
LOW-VOLTAGE CIRCUIT
SAFETY DEVICES AND CONTROLS
Central-heating sensor
(NR)
Allows the modulation board to detect the temperature of the primary
circuit water flow.
If this sensor stops working, burner operation stops both in central-
heating and d.h.w. modes.
It is positioned at the outlet of the main exchanger.
Sensor NTC
10 kohm 25 ºC
Control zone unit (CZ)
(external optional)
Permits boiler operation with 3 area valves /external pumps controlled
by respective room thermostats.
Zone 1 is controlled (times/temperatures) by means of the CAR (i
f
fitted).
See control unit
zone operation
Domestic hot water sensor
(NB)
This enables the modulation board to detect the temperature of the hot
water in the storage tank.
Its failure stops burner operation in domestic hot water phase.
It is inserted inside a bulb holder in contact with the external wall of
the cylinder.
Sensor NTC
10 kohm 25 ºC
External sensor (NE)
(external optional)
Detects external temperature and enables the modulation board to
change the system flow temperature according to outside temperature.
Sensor PTC
1 kohm 25 ºC
Flue pressure switch
(SV)
This acts on the modulation board and enables burner operation when
flue expulsion occurs correctly.
If this is closed with the fan off, the ignition cycle will not start.
2-position switch
Pump pressure switch
(SP)
This acts on the modulation board and permits interrupting power to
the control unit in the event of there being no circulation in the boiler
circuit.
Double-contact
switch
Remote control (CAR)
(external optional)
Permits remote control of boiler iSUM/WINT switch, temperature
adjustment and indication, alarm display, reset, etc.) and acts as a
weekly chrono-thermostat.
Together with the external sensor (NE), allows the modulation board to
change the system flow temperature according to need.
See Remote
Friend Control
operation (CAR)
Room thermostat (TA)
(external optional)
This enables operation in central heating phase when the room
temperature is below that required.
In case of CAR installation, the room thermostat must be disconnected
without resetting the pre-existing jumper P1.
Double clean-
contact switch
LOADS
Display board
This displays burner operation (orange LED), operation in d.h.w. phase (green LED) and in
central-heating or antifreeze phase (green LED) on the control panel.
By means of a dispaly, it indicates the temperature of the boiler, the temperatures set for
d.h.w. and central-heating and the error codes (see modulation board operation).
Modulation coil (MOD) This is powered by the modulation board with variable direct current.
It permits changing gas pressure to the burner.