3.1
internal compartment without the need for purpose
made combustion ventilation. However, if the boiler is
installed in a compartment it is recommended that the
compartment is ventilated for cooling purposes. A
functional diagram of the boiler’s principal
components is given as figure 1. A functional diagram
of the boiler’s principal components is given as
VENTILATION section in user manual
3.2
Range rated from 25kW and 28kW the Capriz 25/
Capriz 28 heat output can be focused to match the
designed heating systems adjustments.
3.3 An electronic control unit, consisting of a PCB,
which includes ignition module, provides direct burner
ignition and flame supervision along with continuous
modulation of the burner’s gas supply.
3.4 An interface unit, which includes boiler adjustment
potentiometers and fault display provides easy service
ability to the boiler.
3.5 Heat transfer to the boiler’s primary hydraulic
circuit is obtained via a primary, gas to water heat
exchanger contained within a hermetically sealed
combustion chamber. A 230 volt, duel speed fan
expels the products of combustion from the
combustion chamber to outside air via an associated
flue system. The fan is activated at the beginning of
each ignition cycle and its operation monitored by
means of negative and positive sensing points
connected to an air pressure switch.
3.6 A secondary heat exchanger allows the
instantaneous transferral of heat from the primary
hydraulic circuit to water destined for domestic hot
water use. The secondary heat exchanger is sized so
as to minimise thermal shock and is protected against
the build up of lime scale by limiting the D.H.W. outlet
water temperature to a maximum of 64°C.
3.7 An integral pump located in the boilers main
hydraulic circuit circulates water through the primary
heat exchanger to either the central heating circuit or
D.H.W. heat exchanger, depending on the demand. In
the event of reduced or interrupted water circulation
in the central heating circuit, a system by-pass should
be fitted as far away from the boiler as possible.
Note: It is no longer permissible to utilise
a non-thermostatic controlled radiator as a by-pass.
3.8 Room temperature can be controlled by the use of an
external room thermostat or temperature regulator.
Note connection of the room thermostat is dependant on
the operating voltage of the thermostat. See section 9.4
& 9.5 for details
3.9 The boiler boiler’s control panel incorporates an LED
display, which indicates the state of operation and fault
defect codes.
4.1
4.2
Using the operating switch the boiler can be set to
operate either on domestic hot water only or
domestic hot water and heating.
Note: Domestic hot water demand draws preference
over heating. During heating periods the boiler will
automatically revert back to heating mode, after
a draw off of hot water, but there will be a 45sec
delay if the No.3 dipswitch is set to the OFF position.
See figure 21.
Depending on demand water is either diverted via
the three port valve to the secondary water-to-water
heat exchanger for domestic hot water or directly to
the heating system. Schematic diagrams showing
the flow within the boiler’s central heating hydraulic
circuit figure 2a and D.H.W. hydraulic circuit figure
2b are given.
3. Boiler Characteristics
4. Operation
CENTRAL HEATING HYDRAULIC CIRCUIT
Figure 2a
Page 7
The Capriz 25 / 28 is a fan flued, wall- mounted
condensing type combination boiler that supplies both
central heating and mains fed domestic hot water.Being
room sealed the boiler may be installed in any room or
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