MAIN FUNCTION
NO
YE
S
P
ERM
A
N
EN
T
M
A
IN
S
U
PPL
Y
T
O
BOI
L
E
R
BOI
L
E
R
DE
MAN
D
F
ROM
SYS
T
E
M
F
an to
start
speed.
Pu
m
p
O
N
.
P
repurge
then ignition
spark
4 seconds
BL
UE
LI
G
H
T
ON
BURNER
LI
T
?
GREEN
F
LAM
E
LI
G
H
T
ON
F
an run
10 seconds
then re-spark
5th
attempt?
L
O
CK
OUT
Stabilisation
then fan low
45 seconds
F
a
n (& gas)
modulation
to ac
hieve
set
temperature
(35-82°
C
)
END
O
F
BOI
L
E
R
DE
MAN
D
Gas valve
OFF
P
u
mp run 3
minutes
F
a
n run 3
0
seconds
Over temperature shut-
down if water tempera-
ture is 5°
C ab
ove set
value.
F
an overrun
3
0
seconds
3 minute wait
Boiler temperature
below 8°
C
Run autofroststat
function
P
R
O
T
E
CTI
O
N
S
Y
S
T
E
M
S
P
u
mp antiseize
P
u
mp run 5 seconds
every 24hrs
NO
YE
S
MAIN FUNCTION
INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER GREENSTAR Ri
8 716 115 168a (06/2008)
51
50
F
A
UL
T
F
IND
IN
G
& D
IA
G
R
A
M
S
