Immergas EOLO Extra 24 kW User manual

EOLO Extra kW
Instant wall-hung boilers
airtight chamber
for outdoors
EOLO Extra kW

1
STEEkW ed 01/06 EOLO Extra kW
Technical Documentation Technical Documentation
EOLO Extra kW
Wall-hung room sealed fan assisted boiler for
outdoors.
EOLO Extra 24 kW
EOLO Extra 28 kW
EOLO Extra 32 kW
EOLO Extra kW is a wall-hung room-sealed fan-assisted
boiler (type C) for central heating and producing domestic
hot water.
e boilers of the EOLO Extra kW series are type-approved
for installing outside the building in the open, using a top
cover kit (optional).
e boiler is available with an output power of 24 kW (20,640
kcal/h), 28 kW (24,080 kcal/h) and 32 kW (27,520 kcal/h).
One of the standard features on the boiler is an antifreeze
system that protects against temperatures as low as -15°C (but
the connecting pipes have to be lagged).
e boiler is easily controlled remotely controlled by a
Remote Control (see the CAR technical data sheet) which works
together with a microprocessor controlled p.c.b. with continuo-
us 2-sensor flame modulation (d.h.w. and central heating).
e knobs on the control panel are for setting boiler ope-
rating parameters. is panel visually displays status and the
functioning mode with the LEDs on it. Malfunctions can also
be seen on the Remote Control display.
e hydraulic circuit is equipped with a water-gas exchan-
ger in copper that uses a new 3-way electric valve group
and a new pump group made in a composite material on
which the circulator and the devices to control the hydraulic
circuit are housed (the system’s absolute pressure switch, a 3-bar
safety valve, an automatic system by-pass, etc.).
General features.
e supply of combustion air to inside the sealed chamber and
the expulsion of fumes are ensured by a fan whose correct ope-
ration is controlled by a differential fumes pressure switch.

2
STEEkW ed 01/06 EOLO Extra kW
Technical DocumentationTechnical Documentation
EOLO Extra 24 kW main dimensions and connections.
Legend:
G - Gas supply
AC - D.h.w. outlet
AF - D.h.w. (cold) inlet
R - System return
M - System delivery
V - Electrical connection
Height (mm) Width (mm) Depth (mm)
775 440 240
CONNECTIONS
GAS DOMESTIC
WATER SYSTEM
G AC AF R M
1/2” 1/2” 1/2” 3/4” 3/4”
EOLO Extra 28-32 kW main dimensions and connections.
Legend:
G - Gas supply
AC - D.h.w. outlet
AF - D.h.w. (cold) inlet
R - System return
M - System delivery
V - Electrical connection
Height (mm) Width (mm) Depth (mm)
775 520 250
CONNECTIONS
GAS DOMESTIC
WATER SYSTEM
G AC AF R M
1/2” 1/2” 1/2” 3/4” 3/4”

3
STEEkW ed 01/06 EOLO Extra kW
Technical Documentation Technical Documentation
Legend:
1 - Stand by LED
2 - Burner on LED
3 - D.h.w. on LED
4 - Central heating on LED
5 - Temperature LED – Ignition stop malfunction
6 - Temperature LED – Flue pressure switch malfunction
7 - Temperature LED – System pressure insufficient malfunction
8 - Temperature LED – Circulation insufficient malfunction
9 - Temperature LED – Delivery probe faulty
10 - Temperature LED – Domestic hot water probe faulty (optional)
11 - Temperature LED – Overheating lock
12 - Stand-by / On / Programming / Reset main switch
13 - Parameters selection knob
14 - Parameters modification knob
15 - Boiler manometer
EOLO Extra kW Control panel.

4
STEEkW ed 01/06 EOLO Extra kW
Technical DocumentationTechnical Documentation
EOLO Extra 24 kW main components.
Legend:
1 - Boiler pressure gauge
2 - Domestic water probe
3 - D.h.w. flow switch
4 - Gas valve
5 - System pressure switch
6 - Burner
7 - Combustion chamber
8 - Airtight chamber
9 - Fan
10 - Testing hole (air A) - (fumes F)
11 - Pressure point with positive signal
12 - Pressure point with negative signal
13 - Flue pressure switch
14 - Delivery probe
15 - Safety thermostat
16 - Draught diverter
17 - Primary exchanger
18 - Ignition and detection electrodes
19 - System expansion vessel
20 - Automatic air vent
21 - Boiler circulator
22 - D.h.w. exchanger
23 - 3-bar valve (motorised)
24 - Automatic by-pass
25 - 3-way safety valve
26 - System draining cock
27 - Domestic water draining fitting
28 - System filling valve

5
STEEkW ed 01/06 EOLO Extra kW
Technical Documentation Technical Documentation
EOLO Extra 28-32 kW main components.
Legenda:
1 - Domestic water draining fitting
2 - Domestic water probe
3 - D.h.w. flow switch
4 - Gas valve
5 - System pressure switch
6 - Burner
7 - Combustion chamber
8 - Airtight chamber
9 - Fan
10 - Testing hole (air A) - (fumes F)
11 - Pressure point with positive signal
12 - Pressure point with negative signal
13 - Flue pressure switch
14 - Delivery probe
15 - Safety thermostat
16 - Draught diverter
17 - Primary exchanger
18 - Ignition and detection electrodes
19 - System expansion vessel
20 - Automatic air vent
21 - Boiler circulator
22 - D.h.w. exchanger
23 - 3-way valve (motorised)
24 - Automatic by-pass
25 - 3-bar safety valve
26 - System draining cock
27 - Boiler pressure gauge
28 - System filling valve

6
STEEkW ed 01/06 EOLO Extra kW
Technical DocumentationTechnical Documentation
EOLO Extra kW hydraulic diagram.
Legend:
1 - D.h.w. flow switch
2 - Flow limiter
3 - System filling valve
4 - Domestic water probe
5 - Gas valve
6 - Burner
7 - Primary exchanger
8 - Draught diverter
9 - Fan
10 - Airtight chamber
11 - Flue pressure switch
12 - Delivery probe
13 - Safety thermostat
14 - System expansion vessel
15 - Automatic air vent
16 - Boiler circulator
17 - System pressure switch
18 - D.h.w. exchanger
19 - 3-way valve
20 - Automatic by-pass
21 - System draining cock
22 - 3-bar safety valve
G - Gas supply
AC - D.h.w. outlet
AF - D.h.w. (cold) inlet
R - System return
M - System delivery
Hot water for central heating and domestic use is produced
by a primary and secondary (d.h.w.) circuit that are engaged
according to requirements.

7
STEEkW ed 01/06 EOLO Extra kW
Technical Documentation Technical Documentation
Primary circuit (boiler circuit).
e primary circuit with relevant control and safety devices
is triggered each time there is a request for central heating
or domestic hot water.
Operation.
e heat contained in the flue produced by combustion is ab-
sorbed by the copper blades of the primary water-gas exchanger
(7) which, in turn, transfers it to the water circulating inside
it by means of the boiler pump (16).
e water is transferred directly into the system or else can
be diverted inside the stainless steel instantaneous plate ex-
changer (18).
is depends on the position of the motorised 3-way valve
(19) which, when idle, lets the water flow through the d.h.w.
exchanger (18); on the other hand, when responding to a heat-
ing request, the flow is diverted to the system delivery (M) and
return (R) pipes.
Flow-head graph.
e trend of the curve that represents the system’s flow-head
ratio depends on how fast the pump is working and on how
the system by-pass is adjusted. Depending on the position, it
provides the system with a higher or a smaller head. e cha-
racteristic curves are shown in the following graphs.
D
Flow-rate l/h
A
Head (m H2O)
EOLO Extra 24 kW
Head (kPa)
Flow-rate l/h
Head (m H2O)
EOLO Extra 28 kW
B
C
A
B
C
D
Head (kPa)
A = Head available to the system on maximum speed with the by-pass off.
B = Head available to the system on maximum speed with the by-pass on.
C = Head available to the system at second speed with the by-pass off.
D = Head available to the system at second speed with the by-pass on.

8
STEEkW ed 01/06 EOLO Extra kW
Technical DocumentationTechnical Documentation
Boiler circulator (1).
It works on the primary circuit return, located immediately
after the 3-way diverter valve to which it is connected.
It is part of the integrated multi-function unit made in a
compound material.
A space on the body houses the automatic air vent (2).
Primary exchanger (1).
It is a water-gas lamellar exchanger with copper pipes and
fins (N° 75 fins 24 kW version) (N° 98 fins 28 and 32 kW
version). e central heating delivery NTC probe (2) and the
overheating safety thermostat (3) are located on the exchanger’s
outlet (delivery).
e four pipes it is made of are connected in series (4).
It is connected to the pump delivery and primary circuit deli-
very by means of pipes with threaded fittings.
1
34
2
Delivery
Return
1
2
EOLO Extra 32 kW
Flow-rate l/h
A
B
C
D
A = Head available to the system on maximum speed with the by-pass off.
B = Head available to the system on maximum speed with the by-pass on.
C = Head available to the system at second speed with the by-pass off.
D = Head available to the system at second speed with the by-pass on.
Head (m H2O)
Head (kPa)