The fan flued hermetic type combination boiler is an apppliance that fires Natural gas in its
combustion chamber for either heating a place or obtaining domestic hot w
different functions at same appliance. For this two different function it has two independent
circuit. One of them is heating circuit and the other is domestic hot water circuit. It is sealed from
the heating place. So well ventilatio
n conditions is not a necessity in place where the appliance
mounted .
1.1. DESCRIPTIONS AND OPERATION PRINCIPLES OF COMPONENTS / PARTS
Burner : Gas that comes from gas valve fires in burner and produces heat.
Ignition electrodes : sparks occurs between the two electrodes for igniting the burner.
Gas valve : it opens or closes the gas channel and regulates the burner pressure.
Ignition module : it works with gas valve together and ignite the burner by means of producing
high voltage. It starts the fan and
evaluates signals coming from air pressure switch and flame
sense electrode.
Injectors : They guide gas to the burner.
Fan : it gets the fresh air for combustion and blow the combustion products out of hermetic
chamber.
Gas manifold : the injectors are mounted on gas manifold.
Combustion chamber : The heat isolated combustion chamber guides the burner flame to the heat
exchanger.
Primary Heat exchanger : It transfers the heat energy in flame to the water.
Automatic air vent : it purges the air in heating circuit automatically.
Air pressure switch : It checks the pressure difference between the hermetic chamber and the
outer space and sends signal to the ignition module about the fan operation.
Overheat safety thermostat : It sends signal to the control card
about the water temperature which
exceeds 110 ºC. It interrupts the boiler if the water temperature exceed 110 ºC. It has a manual
reset button at rear side.
Hydraulic block : It has several connections for components, pipes and inlets, outlets to the boil
(For example water pressure sensor, safety valve, expansion vessel etc.) It has an automatic by-
pass valve inside. It consists of two independent parts which are connected together by means of
pipes.
Three way valve : it is one part of the hydraulic bl
ock. It guides the hot water to heating circuit or
domestic hot water exchanger.
Domestic hot water heat exchanger : It transfers the heat energy in hot water of heating circuit to
the domestic water. It is integrated with primary heat exchanger.
Fan hood : it collects combustion products and guides to the fan.
Flue connection kit : It connects the outer space and combustion chamber for getting fresh air and
blow the combustion products out of boiler.
Hermetic chamber : The combustion chamber, burner, heat
exchanger, fan and fan hood is placed
inside the hermetic chamber.
Safety valve : It prevents the heating circuit against the water pressure increment excessively.
(The water pressure can not exceed 3 bar.)
Control card : The control card evaluates the si
gnals which come from sensors and thermostats.
And it makes modulation for control the gas valve. It controls all systems of boiler. It is central
control unit of the boiler.
Water flow sensor : it senses the domestic hot water demands and sends signal to the control card.
