INTRODUCTION TO THE BOILER
General description of the boiler
The wall hung gas boiler is a fuel gas-consuming appliance which has the role of
turning the fuel gas power into thermal energy through burning.
This appliance runs unsupervised due to its protection and control systems.
The boiler is made of many parts that we are going to describe in the following
chapters.
The gas enters inside the boiler through the gas feeding circuit made of a coupling
and a reducing valve which will be set at 20 mbar for G20 A(L) and A(H) subgroups.
The reducing valve will be set at 37 mbar for LPG (propane subgroups and propane-
butane mixtures). Thus it gets into the gas valve which has the role of controlling the
gas discharge at the outlet to the burner.
The ignition achieves by flame activating by an ignition electrode, by means of
an ignition transformer.
During the combustion, the flame sensing is made by an ionization sensor.
The boiler type with forced draft is provided with a fan which evacuates the
exhaust gases. In the initiation phase, this evacuates an air volume to provide an
unexplosive ignition. The explosive ignition may occur due to a gas storage from the
non-operating period.
The combustion chamber, as a plate parallelotope, interior ceramics fibre-lined,
is designed to allow the transfer to the exchanger with less heat leakages.
In case of the CH circuit of the two heat exchangers type, the heat resulted from
fuel gas ignition is taken over by the monothermal heat exchanger and sent to the
thermal agent (water) which is delivered by the circulating pump through the heating
installation. In case of on the DHW circuit, a water discharge is detected by the
flowmeter, the 3- way gas valve is energized. The 3- way gas valve achieves the
transition from the central heating circuit on the short circuit through the plate heat
exchanger (the main plate heat exchanger) and the heat transfer is realized by means
of this to the DHW circuit (the secondary plate heat exchanger).
The scavenging is realized by means of the fan.
The running protection and control are performed electronically. The boiler setting
is made from the control board (see the chapter concerning this subject).
DESCRIPTION OF THE BOILER
3
BOILER
TYPE
C15 SPV 24 MEFM
Useful power
Accessories
[kcal/h]
The fan
The pump
The
expansion
vessel
DHW
instant
production
20670
X
X
X
X
SYMBOLS
S- with instant production of DHW (without cumulation)
P- with pump
V-with closed expansion vessel
24-the maximum power output in kW
M- the burner is supplied by a continuous modulating valve
E- the ignition and the control of the flame are electronically-made
F-the forced scavenging
M-monothermal
OPTIMUS MT
