Immergas EOLO Mini User manual

EOLO Mini
24-28 kW Special
Compact wall-hung
instantaneous boilers
with sealed-room
EOLO Mini 24-28 kW Special

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STEMkW Special ed 01/08 EOLO Mini kW Special
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EOLO Mini 24-28 kW Special
Compact instantaneous wall-hung room sealed
fan-assisted boiler (type C).
EOLO Mini 24 kW Special
EOLO Mini 28 kW Special
EOLO Mini kW Special is a wall-hung room-sealed fan-assi-
sted boiler (type C) for central heating and producing domestic
hot water, characterised by its extremely compact size.
e boiler is available with an output power of 24 kW Special
(20,640 kcal/h) and 28 kW Special (24,080 kcal/h).
e boilers of the EOLO Mini kW Special series are type-
approved also for installation outside the building in a partly
sheltered location.
Note: By a partly sheltered location we mean a place where the
appliance is not exposed directly to the weather (rain, snow, hail,
etc.).
e boiler is tted with a new microprocessor controlled p.c.b.
that electronically controls burner ignition, central heating and
d.h.w. temperatures and continuous ame modulation.
With the new electronics the boiler can be connected to a
Remote Control (CAR or CRD) letting you easily control the
boiler remotely.
One of the standard features on the boiler is an antifreeze
system that protects against temperatures as low as -5°C
(optional down to -15°C).
e hydraulic circuit is equipped with a water-gas exchan-
ger in copper, a pump group made in a composite material
and a new 3-way electric valve group that allows, according
to requirements, boiler water to circulate in the central heating
system or in a STAINLESS STEEL plate exchanger for the
General features.
instant production of domestic hot water. e primary circuit
is tted with an automatic by-pass and a 3-bar safety valve.
A d.h.w. ow switch enables boiler activation if there is a
d.h.w. request.
e supply of combustion air inside the sealed chamber and
the expulsion of fumes are ensured by a fan whose correct
operation is controlled by a dierential pressure switch.
e boiler’s operating parameters are set by turning the knobs,
with the visual display of status, mode and malfunctions by
means of the LEDs on the easy-to-read display panel.

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STEMkW Special ed 01/08 EOLO Mini kW Special
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Legend:
G - Gas supply
AC - Domestic hot water ow
AF - Domestic cold water inlet
R - C.h. return
M - C.h. ow
V - Power supply connection
EOLO Mini 24 kW Special main dimensions and connections.
EOLO Mini 28 kW Special main dimensions and connections.
Legend:
G - Gas supply
AC - Domestic hot water ow
AF - Domestic cold water inlet
R - C.h. return
M - C.h. ow
V - Power supply connection
Height (mm) Width (mm) Depth (mm)
790 450 310
Connections
GAS DOMESTIC
WATER SYSTEM
GAC AF R M
3/4” 1/2” 1/2” 3/4” 3/4”
Height (mm) Width (mm) Depth (mm)
790 450 250
Connections
GAS DOMESTIC
WATER SYSTEM
GAC AF R M
3/4” 1/2” 1/2” 3/4” 3/4”

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STEMkW Special ed 01/08 EOLO Mini kW Special
Technical Documentation Technical Documentation
Legend:
1 - Sample point (A air) - (F ue)
2 - Fan
3 - D.h.w. ow switch
4 - Gas valve
5 - Filling valve
6 - Positive signal pressure point
7 - Negative signal pressure point
8 - Flue pressure switch
9 - Sealed chamber
10 - Flow probe
11 - Safety thermostat
12 - System expansion vessel
EOLO Mini 24 kW Special main components.
13 - Combustion chamber
14 - Automatic vent valve
15 - Boiler pump
16 - 3-bar safety valve
17 - D.h.w. heat exchanger
18 - 3-way valve (motorized)
19 - Automatic by-pass
20 - Draining valve
21 - Flue hood
22 - Primary heat exchanger
23 - Ignition and detection electrodes
24 - Burner
Note: Coupling system (OPTIONAL)

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STEMkW Special ed 01/08 EOLO Mini kW Special
Technical DocumentationTechnical Documentation
Legend:
1 - Sample point (A air) - (F ue)
2 - Fan
3 - D.h.w. ow switch
4 - Gas valve
5 - Filling valve
6 - Positive signal pressure point
7 - Negative signal pressure point
8 - Flue pressure switch
9 - Sealed chamber
10 - Flow probe
11 - Safety thermostat
12 - System expansion vessel
13 - Combustion chamber
EOLO Mini 24 kW Special main components.
14 - Automatic vent valve
15 - Boiler pump
16 - 3-bar safety valve
17 - D.h.w. heat exchanger
18 - 3-way valve (motorized)
19 - Automatic by-pass
20 - Draining valve
21 - Flue hood
22 - Primary heat exchanger
23 - Ignition and detection electrodes
24 - Burner
Note: Coupling system (OPTIONAL)

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STEMkW Special ed 01/08 EOLO Mini kW Special
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Legend:
1 - Burner operating LED
2 - D.h.w. operating LED
3 - C.h. operating LED
4 - Temperature LED - Malfunction - circulation insu-
cient
5 - Temperature LED - Malfunction - ow probe
6 - Temperature LED - Malfunction - ignition block
Control Panel.
7 - Temperature LED - Malfunction - overheating block
8 - Temperature LED - Malfunction - ue pressure switch
9 - D.h.w. stand-by selector/Remote Control - D.h.w. and C.h.-
Reset
10 - D.h.w. temperature selector
11 - C.h. temperature selector
12 - Boiler gauge

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STEMkW Special ed 01/08 EOLO Mini kW Special
Technical DocumentationTechnical Documentation
Legend:
1 - D.h.w. ow switch
2 - Flow limiter
3 - Filling valve
4 - Gas valve
5 - Burner
6 - Primary heat exchanger
7 - Flue hood
8 - Fan
9 - Sealed chamber
10 - Flue pressure switch
11 - Flow probe
12 - Safety thermostat
13 - System expansion vessel
14 - Automatic vent valve
15 - Boiler pump
16 - D.h.w. heat exchanger
17 - 3-way valve (motorized)
18 - Automatic by-pass
19 - Draining valve
20 - 3-bar safety valve
G - Gas supply
AC - Domestic hot water ow
AF - Domestic cold water inlet
R - System return
M - System ow
Hydraulic circuit.
e primary circuit, with relevant control and safety devices,
is operated each time either a central heating or d.h.w.
request is made.
Operation.
e heat contained in the fumes produced by combustion
is absorbed by the copper blades of the water-gas primary
exchanger (6) which, in turn, transfers it to the water circula-
ting inside thanks to the boiler circulator (15).
e water is transferred directly into the system or can be
deviated to the instant stainless steel plate exchanger (16).
is depends on the position of the motorised 3-way diverter
valve (17) which, when idle allows the water to ow to the
d.h.w. exchanger (16) while if a central heating request is
made it deviates the ow to the system’s ow (M) and return
(R) pipes.
Primary circuit (Boiler Circuit).
e hot water for central heating and domestic use is produ-
ced by a primary and a secondary (d.h.w.) circuits that work
as required.

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Head ow rate graph.
e course of the curve that represents the ow rate/head ratio
available for the system depends on how fast the circulator is
working which, depending on the position, gives the system
a bigger or smaller head. e characteristic curves are shown
in the following graphs.
A = Head available to the system at third speed (with automatic by-pass)
B = Head available to the system at second speed (with automatic by-pass)
EOLO Mini 28 kW Special
EOLO Mini 24 kW Special
Head (m H2O)
Flow rate (l/h)
Head (kPa)
A
B
A
B
Head (m H2O)
Head (kPa)
Flow rate (l/h)

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Boiler circulator (1).
e pump works on the primary circuit return; it is part of the
pump body unit made in a composite material.
e automatic air vent (2) is housed directly on the body.
1
2
Primary exchanger (1).
It is a lamellar water-gas exchanger with copper tubes and ns
and at whose outlet (ow) the central heating NTC ow probe
(6) and the overtheating safety thermostat (2) are located.
e four pipes it is made of are connected in series (1).
It is connected to the circulator ow and to the primary circuit
ow by means of push-tted pipes (3) and O rings (5) and
locked with forks (4).
e exchangers of the 24 and 28 versions dier in the number
of ns (86 in the 24 version and 103 in the 28 version) and in the
dierent layout of the ow and return pipes (see drawing).
1
34
5
2
6
Flow
Return
1
34
5
2
6
Flow
Return
EOLO Mini 28 kW Special
EOLO Mini 24 kW Special