Sime Planet Dewy 25 BF Manual Del Usuario página 112

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 win-
ding, so that the valve cannot open.
– Ignition electrode fails to spark
In the boiler, only the gas to the burner
is seen to open. After 10 sec. the war-
ning light indicating equipment "lock-
out" lights up.
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;
– No detection of flame
The continuous spark discharge of the
electrode is noted starting from ignition
even though the burner is lit.
Af t er 10 seconds have elapsed, the
sparks cease, the burner goes out, and
the warning light indicating equipment
"lock-out" lights up.
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.
3.4 FLOW SWITCH SAFETY VALVE
A flow switch safety valve intervenes,
blocking the operation of the burner if the
Connettore J2
Connector "TA"
KEY
TA-TA1
VZ-VZ1
110
600
500
400
300
200
100
boiler is without water due to the formation
of an air lock in the heat exchanger or if the
circulator is not working, or because the
"Aqua Guard" filter is obstructed with impu-
rities.
NOTE: If replacing the flow switch valve,
make sure that the arrow stamped on the
valve points in the same direction as the
flow of water.
3.5 SYSTEM AVAILABLE HEAD
The head available for the heating plant is
CIRCUIT WITH ZONE VALVES
CIRCUITO CON VALVOLE DI ZONA
L
CR CR1
TA
VZ
TA
N
NOTA: I relé vengono impiegati solo
NOTE: Relays are used only if the area
nel caso le valvole di zona siano
valves have no microswitches.
prive di micro.
Zone room stat
Zone gas valve
0
200 400 600
TA
TA
1
R VZ
R
1
1
P-P1 Zone pump
R-R1 Zone relay
CR-CR1 Zone microvalve or relay contact
con by-pass
senza by-pass
800 1000 1200 1400 1600
FLOW RATE (l/h)
PORTATA (l/h)
shown as a function of the flow in graph in
fig. 21.
3.6 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 TA-CR-SE (J2) connector of the cir-
cuit board after having removed the jum-
per (fig. 22).
CIRCUIT WITH ZONE PUMPS
CIRCUITO CON POMPE DI ZONA
L
TA TA1
P1
P
R
N
Fig. 21
R1
Fig. 22