as shown in the diagram.
Rotate the selector to summer or winter,
the red led should light up.
The boiler is now ready to start working
upon demand for heating or drawing off of
D.H.W.; a discharge current is sent to the
ignition electrode through the programmer,
and the gas valve opens at the same time.
Burner ignition normally takes place within
2 or 3 seconds.
However, it is possible for ignition failures
to occur, with consequent activation of
signal indicating that the control box has
“locked out”.
–
Gas failure
The control box runs through the cycle
normally sending electric power to the
ignition electrode.
The electrode continues spark discharge
for a maximum of 10 sec.
If the burner does not ignite, the control
box “locks out”.
This may occur upon first ignition or
after long periods of boiler lay-off when
there is air in the pipes.
It may be caused by the gas cock being
closed or by one of the valve coils having
a break in the winding, so that the valve
cannot open. The HONEYWELL valve
connector is defective.
–
Ignition electrode fails to spark
In the boiler, only the gas to the burner is
seen to open. After 10 sec. the control
box “locks out”.
This may be due to a break in the wire of
the electrode or to the wire not properly
fastened to the electric terminal of the
control box; or else, the transformer has
burnt out.
–
No detection of flame
The continuous spark discharge of the
electrode is noted starting from ignition
even though the burner is lit.
Af ter 10 seconds have elapsed, the
sparks cease, the burner goes out, and
the warning light indicating equipment
“lock-out” lights up.
This occurs when the position of phase
and neutral has not been respected on
the terminal block.
There could have a break in the wire of
the sensing electrode or the electrode
itself is touching earth: the electrode is
worn out and needs replacing. The con-
trol box is defective.
When there is a sudden voltage failure, the
burner shuts out immediately; when power
supply returns, the boiler will start up again
automatically.
3.3.2
Operating cycle
At each start-up the programmers perform
a self-check which, if there is a malfunction
or parasite flame signal, disables the pro-
gram start.
The programmer will not start when the air
pressure switch is not in the non-venting
position.
3.4
“25 OF - 30 OF” SMOKE
SAFETY DEVICE
This is a safety device against possible
smoke emission into the ambience (14 fig.
3). The safety device goes into action by
blocking operation of the gas valve when the
return of the smoke into the ambience is
continuous and in quantities that might con-
stitute a danger.
The intervention of the device locks out the
appliance because the burner has not igni-
ted. In this case, place the rotary switch to
the (
) position must be pressed for the
boiler to restart automatically.
Should the boiler continue to “lock out”, it will
be necessary to make a careful check on
the flue pipe, making all the necessary modi-
fications and amendments so that it can
work properly.
3.5
“25 BF - 30 BF” SMOKE
PRESSURE SWITCH
The pressure switch is factory set at the
optimal values of 4.5 - 6 mm H
2
O (
“25”
vers.) and 10-13 mm H2O (
“30”
vers.).
This enables the boilers operation even
with air intake and smoke outlet pipes at
the maximum limit of the length allowed (9
fig. 3).
Impurities and possible formations of
condensate, which are more likely in cold
periods of the year, could lead the pres-
sure switch not to work and the boiler
fail to start.
3.6
NO WATER FLOW SAFETY DEVICE
The boiler has a flow switch (8 fig. 7) which
is tripped when it does not detect water
flow in the primary circuit (>400 l/h), pre-
venting the burner from functioning.
To start the burner again, check the pres-
sure in the system and make sure that
the pump and the flow switch are working
properly.
3.7
SYSTEM AVAILABLE HEAD
The head available for the heating plant is
shown as a function of the flow in graph in
fig. 24.
3.8
TIME PROGRAMMER (optional)
The control panel is designed to allocate a
timer-programmer, code 8092203, which
can be supplied upon request. To fit the
timer, remove the housing blanking piece
from the control panel and, with the panel
open, fit the timer to the panel using the
screws supplied therein.
Remove the faston that links the terminal 3
of the rotary switch and connect it to the
terminal 3 of the time-clock.
Connect the unit as shown in the wiring dia-
gram (fig. 25).
3.9
MAINS ELECTRICITY
CONNECTION
Use a separate electricity supply to con-
nect the room stats and relative zone val-
ves or pumps.
The micro or relay contact connection is
made to terminals 22-23 (TA) of the cir-
cuit board after having removed the jum-
per (fig. 26).
86
0
600
200
1600
1400
1200
1000
800
600
400
PORTATA (l/h)
PREV
ALENZA RESIDU
A (mbar)
500
400
100
200
300
con by-pass
senza by-pass
25
30
25
30
For
mat - Plane
t - Open
Fig. 24
FLOW RATE (l/h)
RESIDU
AL
HEAD
(mbar)
