CENTRAL HEATING FUNCTION
CENTRAL HEATING FUNCTION
INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER BOSCH GREENSTAR 12i System/24i System
8 716 107 375a (02/05)
55
FA
U
LT
F
IN
D
IN
G
& D
IA
G
R
A
M
S
NO
YE
S
PO
WE
R
SW
IT
CH
ON
CE
NTRAL
HE
A
T
IN
G
DE
MAN
D
F
an to
start
speed.
Diverter valve
in C
H
position
P
ump O
N
.
IG
N
IT
ION
SE
QU
E
N
CE
(see detail)
BL
UE
LI
G
H
T
ON
BURNER
L
IT?
GREEN
F
LAM
E
LI
G
H
T
ON
Stop spark.
W
ait
10 seconds
5th
attempt?
L
O
CK
OUT
10 second
stabilisation
period.
F
an (& gas)
modulation
to ac
hieve
set
temperature
(4
0-82°
C)
E
N
D OF
BOI
L
E
R
DE
MAN
D
Gas valve
OFF
P
ump run 3
minutes
F
an run 3
0
seconds
Over temperature shut-
down if water tempera-
ture is 5°
C ab
ove set
value.
Gas valve O
F
F.
F
an overrun
3
0
seconds
3 minute wait
Spark
ignition
4 seconds
NO
YE
S
Room
thermostat O
N
(and/or link fitted
at S
T10)
AND
F
acia mounted
programmer O
N
AND
Temperature
control
ON
IG
N
IT
ION
SEQU
E
N
C
E
